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_ksyscall_opts {
533 /* size of this struct, for forward/backward compatibility */
535 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
537 /* attach as return probe? */
541 #define bpf_ksyscall_opts__last_field retprobe
544 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
545 * to kernel syscall handler of a specified syscall. Optionally it's possible
546 * to request to install retprobe that will be triggered at syscall exit. It's
547 * also possible to associate BPF cookie (though options).
549 * Libbpf automatically will determine correct full kernel function name,
550 * which depending on system architecture and kernel version/configuration
551 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
552 * attach specified program using kprobe/kretprobe mechanism.
554 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
555 * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
557 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
558 * not handle all the calling convention quirks for mmap(), clone() and compat
559 * syscalls. It also only attaches to "native" syscall interfaces. If host
560 * system supports compat syscalls or defines 32-bit syscalls in 64-bit
561 * kernel, such syscall interfaces won't be attached to by libbpf.
563 * These limitations may or may not change in the future. Therefore it is
564 * recommended to use SEC("kprobe") for these syscalls or if working with
565 * compat and 32-bit interfaces is required.
567 * @param prog BPF program to attach
568 * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
569 * @param opts Additional options (see **struct bpf_ksyscall_opts**)
570 * @return Reference to the newly created BPF link; or NULL is returned on
571 * error, error code is stored in errno
573 LIBBPF_API struct bpf_link *
574 bpf_program__attach_ksyscall(const struct bpf_program *prog,
575 const char *syscall_name,
576 const struct bpf_ksyscall_opts *opts);
578 struct bpf_uprobe_opts {
579 /* size of this struct, for forward/backward compatibility */
581 /* offset of kernel reference counted USDT semaphore, added in
582 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
584 size_t ref_ctr_offset;
585 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
587 /* uprobe is return probe, invoked at function return time */
589 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified
590 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while
591 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an
592 * offset within a function, specify func_name and use func_offset argument to specify
593 * offset within the function. Shared library functions must specify the shared library
596 const char *func_name;
597 /* uprobe attach mode */
598 enum probe_attach_mode attach_mode;
601 #define bpf_uprobe_opts__last_field attach_mode
604 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
605 * to the userspace function which is found by binary path and
606 * offset. You can optionally specify a particular proccess to attach
607 * to. You can also optionally attach the program to the function
608 * exit instead of entry.
610 * @param prog BPF program to attach
611 * @param retprobe Attach to function exit
612 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
613 * -1 for all processes
614 * @param binary_path Path to binary that contains the function symbol
615 * @param func_offset Offset within the binary of the function symbol
616 * @return Reference to the newly created BPF link; or NULL is returned on error,
617 * error code is stored in errno
619 LIBBPF_API struct bpf_link *
620 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
621 pid_t pid, const char *binary_path,
625 * @brief **bpf_program__attach_uprobe_opts()** is just like
626 * bpf_program__attach_uprobe() except with a options struct
627 * for various configurations.
629 * @param prog BPF program to attach
630 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
631 * -1 for all processes
632 * @param binary_path Path to binary that contains the function symbol
633 * @param func_offset Offset within the binary of the function symbol
634 * @param opts Options for altering program attachment
635 * @return Reference to the newly created BPF link; or NULL is returned on error,
636 * error code is stored in errno
638 LIBBPF_API struct bpf_link *
639 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
640 const char *binary_path, size_t func_offset,
641 const struct bpf_uprobe_opts *opts);
643 struct bpf_usdt_opts {
644 /* size of this struct, for forward/backward compatibility */
646 /* custom user-provided value accessible through usdt_cookie() */
650 #define bpf_usdt_opts__last_field usdt_cookie
653 * @brief **bpf_program__attach_usdt()** is just like
654 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
655 * Statically Defined Tracepoint) attachment, instead of attaching to
656 * user-space function entry or exit.
658 * @param prog BPF program to attach
659 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
660 * -1 for all processes
661 * @param binary_path Path to binary that contains provided USDT probe
662 * @param usdt_provider USDT provider name
663 * @param usdt_name USDT probe name
664 * @param opts Options for altering program attachment
665 * @return Reference to the newly created BPF link; or NULL is returned on error,
666 * error code is stored in errno
668 LIBBPF_API struct bpf_link *
669 bpf_program__attach_usdt(const struct bpf_program *prog,
670 pid_t pid, const char *binary_path,
671 const char *usdt_provider, const char *usdt_name,
672 const struct bpf_usdt_opts *opts);
674 struct bpf_tracepoint_opts {
675 /* size of this struct, for forward/backward compatibility */
677 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
680 #define bpf_tracepoint_opts__last_field bpf_cookie
682 LIBBPF_API struct bpf_link *
683 bpf_program__attach_tracepoint(const struct bpf_program *prog,
684 const char *tp_category,
685 const char *tp_name);
686 LIBBPF_API struct bpf_link *
687 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
688 const char *tp_category,
690 const struct bpf_tracepoint_opts *opts);
692 LIBBPF_API struct bpf_link *
693 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
694 const char *tp_name);
696 struct bpf_trace_opts {
697 /* size of this struct, for forward/backward compatibility */
699 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
702 #define bpf_trace_opts__last_field cookie
704 LIBBPF_API struct bpf_link *
705 bpf_program__attach_trace(const struct bpf_program *prog);
706 LIBBPF_API struct bpf_link *
707 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
709 LIBBPF_API struct bpf_link *
710 bpf_program__attach_lsm(const struct bpf_program *prog);
711 LIBBPF_API struct bpf_link *
712 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
713 LIBBPF_API struct bpf_link *
714 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
715 LIBBPF_API struct bpf_link *
716 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
717 LIBBPF_API struct bpf_link *
718 bpf_program__attach_freplace(const struct bpf_program *prog,
719 int target_fd, const char *attach_func_name);
721 struct bpf_netfilter_opts {
722 /* size of this struct, for forward/backward compatibility */
730 #define bpf_netfilter_opts__last_field flags
732 LIBBPF_API struct bpf_link *
733 bpf_program__attach_netfilter(const struct bpf_program *prog,
734 const struct bpf_netfilter_opts *opts);
736 struct bpf_tcx_opts {
737 /* size of this struct, for forward/backward compatibility */
742 __u64 expected_revision;
745 #define bpf_tcx_opts__last_field expected_revision
747 LIBBPF_API struct bpf_link *
748 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
749 const struct bpf_tcx_opts *opts);
753 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
754 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
756 struct bpf_iter_attach_opts {
757 size_t sz; /* size of this struct for forward/backward compatibility */
758 union bpf_iter_link_info *link_info;
761 #define bpf_iter_attach_opts__last_field link_info_len
763 LIBBPF_API struct bpf_link *
764 bpf_program__attach_iter(const struct bpf_program *prog,
765 const struct bpf_iter_attach_opts *opts);
767 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
770 * @brief **bpf_program__set_type()** sets the program
771 * type of the passed BPF program.
772 * @param prog BPF program to set the program type for
773 * @param type program type to set the BPF map to have
774 * @return error code; or 0 if no error. An error occurs
775 * if the object is already loaded.
777 * This must be called before the BPF object is loaded,
778 * otherwise it has no effect and an error is returned.
780 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
781 enum bpf_prog_type type);
783 LIBBPF_API enum bpf_attach_type
784 bpf_program__expected_attach_type(const struct bpf_program *prog);
787 * @brief **bpf_program__set_expected_attach_type()** sets the
788 * attach type of the passed BPF program. This is used for
789 * auto-detection of attachment when programs are loaded.
790 * @param prog BPF program to set the attach type for
791 * @param type attach type to set the BPF map to have
792 * @return error code; or 0 if no error. An error occurs
793 * if the object is already loaded.
795 * This must be called before the BPF object is loaded,
796 * otherwise it has no effect and an error is returned.
799 bpf_program__set_expected_attach_type(struct bpf_program *prog,
800 enum bpf_attach_type type);
802 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
803 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
805 /* Per-program log level and log buffer getters/setters.
806 * See bpf_object_open_opts comments regarding log_level and log_buf
809 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
810 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
811 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
812 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
815 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
816 * for supported BPF program types:
817 * - BTF-aware raw tracepoints (tp_btf);
818 * - fentry/fexit/fmod_ret;
821 * @param prog BPF program to set the attach type for
822 * @param type attach type to set the BPF map to have
823 * @return error code; or 0 if no error occurred.
826 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
827 const char *attach_func_name);
830 * @brief **bpf_object__find_map_by_name()** returns BPF map of
831 * the given name, if it exists within the passed BPF object
832 * @param obj BPF object
833 * @param name name of the BPF map
834 * @return BPF map instance, if such map exists within the BPF object;
837 LIBBPF_API struct bpf_map *
838 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
841 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
843 LIBBPF_API struct bpf_map *
844 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
846 #define bpf_object__for_each_map(pos, obj) \
847 for ((pos) = bpf_object__next_map((obj), NULL); \
849 (pos) = bpf_object__next_map((obj), (pos)))
850 #define bpf_map__for_each bpf_object__for_each_map
852 LIBBPF_API struct bpf_map *
853 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
856 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
857 * BPF map during BPF object load phase.
858 * @param map the BPF map instance
859 * @param autocreate whether to create BPF map during BPF object load
860 * @return 0 on success; -EBUSY if BPF object was already loaded
862 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
863 * BPF map. By default, libbpf will attempt to create every single BPF map
864 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
865 * and fill in map FD in BPF instructions.
867 * This API allows to opt-out of this process for specific map instance. This
868 * can be useful if host kernel doesn't support such BPF map type or used
869 * combination of flags and user application wants to avoid creating such
870 * a map in the first place. User is still responsible to make sure that their
871 * BPF-side code that expects to use such missing BPF map is recognized by BPF
872 * verifier as dead code, otherwise BPF verifier will reject such BPF program.
874 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
875 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
878 * @brief **bpf_map__fd()** gets the file descriptor of the passed
880 * @param map the BPF map instance
881 * @return the file descriptor; or -EINVAL in case of an error
883 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
884 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
886 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
887 /* get/set map type */
888 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
889 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
890 /* get/set map size (max_entries) */
891 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
892 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
893 /* get/set map flags */
894 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
895 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
896 /* get/set map NUMA node */
897 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
898 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
899 /* get/set map key size */
900 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
901 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
902 /* get map value size */
903 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
905 * @brief **bpf_map__set_value_size()** sets map value size.
906 * @param map the BPF map instance
907 * @return 0, on success; negative error, otherwise
909 * There is a special case for maps with associated memory-mapped regions, like
910 * the global data section maps (bss, data, rodata). When this function is used
911 * on such a map, the mapped region is resized. Afterward, an attempt is made to
912 * adjust the corresponding BTF info. This attempt is best-effort and can only
913 * succeed if the last variable of the data section map is an array. The array
914 * BTF type is replaced by a new BTF array type with a different length.
915 * Any previously existing pointers returned from bpf_map__initial_value() or
916 * corresponding data section skeleton pointer must be reinitialized.
918 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
919 /* get map key/value BTF type IDs */
920 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
921 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
922 /* get/set map if_index */
923 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
924 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
925 /* get/set map map_extra flags */
926 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
927 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
929 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
930 const void *data, size_t size);
931 LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
934 * @brief **bpf_map__is_internal()** tells the caller whether or not the
935 * passed map is a special map created by libbpf automatically for things like
936 * global variables, __ksym externs, Kconfig values, etc
937 * @param map the bpf_map
938 * @return true, if the map is an internal map; false, otherwise
940 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
943 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
944 * BPF map should be pinned. This does not actually create the 'pin'.
945 * @param map The bpf_map
946 * @param path The path
947 * @return 0, on success; negative error, otherwise
949 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
952 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
953 * BPF map should be pinned.
954 * @param map The bpf_map
955 * @return The path string; which can be NULL
957 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
960 * @brief **bpf_map__is_pinned()** tells the caller whether or not the
961 * passed map has been pinned via a 'pin' file.
962 * @param map The bpf_map
963 * @return true, if the map is pinned; false, otherwise
965 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
968 * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
969 * for the BPF map. This increments the reference count on the
970 * BPF map which will keep the BPF map loaded even after the
971 * userspace process which loaded it has exited.
972 * @param map The bpf_map to pin
973 * @param path A file path for the 'pin'
974 * @return 0, on success; negative error, otherwise
976 * If `path` is NULL the maps `pin_path` attribute will be used. If this is
977 * also NULL, an error will be returned and the map will not be pinned.
979 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
982 * @brief **bpf_map__unpin()** removes the file that serves as a
983 * 'pin' for the BPF map.
984 * @param map The bpf_map to unpin
985 * @param path A file path for the 'pin'
986 * @return 0, on success; negative error, otherwise
988 * The `path` parameter can be NULL, in which case the `pin_path`
989 * map attribute is unpinned. If both the `path` parameter and
990 * `pin_path` map attribute are set, they must be equal.
992 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
994 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
995 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
998 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
999 * corresponding to provided key.
1000 * @param map BPF map to lookup element in
1001 * @param key pointer to memory containing bytes of the key used for lookup
1002 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1003 * @param value pointer to memory in which looked up value will be stored
1004 * @param value_sz size in byte of value data memory; it has to match BPF map
1005 * definition's **value_size**. For per-CPU BPF maps value size has to be
1006 * a product of BPF map value size and number of possible CPUs in the system
1007 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1008 * per-CPU values value size has to be aligned up to closest 8 bytes for
1009 * alignment reasons, so expected size is: `round_up(value_size, 8)
1010 * * libbpf_num_possible_cpus()`.
1011 * @flags extra flags passed to kernel for this operation
1012 * @return 0, on success; negative error, otherwise
1014 * **bpf_map__lookup_elem()** is high-level equivalent of
1015 * **bpf_map_lookup_elem()** API with added check for key and value size.
1017 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1018 const void *key, size_t key_sz,
1019 void *value, size_t value_sz, __u64 flags);
1022 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1023 * map that corresponds to provided key.
1024 * @param map BPF map to insert to or update element in
1025 * @param key pointer to memory containing bytes of the key
1026 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1027 * @param value pointer to memory containing bytes of the value
1028 * @param value_sz size in byte of value data memory; it has to match BPF map
1029 * definition's **value_size**. For per-CPU BPF maps value size has to be
1030 * a product of BPF map value size and number of possible CPUs in the system
1031 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1032 * per-CPU values value size has to be aligned up to closest 8 bytes for
1033 * alignment reasons, so expected size is: `round_up(value_size, 8)
1034 * * libbpf_num_possible_cpus()`.
1035 * @flags extra flags passed to kernel for this operation
1036 * @return 0, on success; negative error, otherwise
1038 * **bpf_map__update_elem()** is high-level equivalent of
1039 * **bpf_map_update_elem()** API with added check for key and value size.
1041 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1042 const void *key, size_t key_sz,
1043 const void *value, size_t value_sz, __u64 flags);
1046 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1047 * corresponds to provided key.
1048 * @param map BPF map to delete element from
1049 * @param key pointer to memory containing bytes of the key
1050 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1051 * @flags extra flags passed to kernel for this operation
1052 * @return 0, on success; negative error, otherwise
1054 * **bpf_map__delete_elem()** is high-level equivalent of
1055 * **bpf_map_delete_elem()** API with added check for key size.
1057 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1058 const void *key, size_t key_sz, __u64 flags);
1061 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1062 * corresponding to provided key and atomically delete it afterwards.
1063 * @param map BPF map to lookup element in
1064 * @param key pointer to memory containing bytes of the key used for lookup
1065 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1066 * @param value pointer to memory in which looked up value will be stored
1067 * @param value_sz size in byte of value data memory; it has to match BPF map
1068 * definition's **value_size**. For per-CPU BPF maps value size has to be
1069 * a product of BPF map value size and number of possible CPUs in the system
1070 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1071 * per-CPU values value size has to be aligned up to closest 8 bytes for
1072 * alignment reasons, so expected size is: `round_up(value_size, 8)
1073 * * libbpf_num_possible_cpus()`.
1074 * @flags extra flags passed to kernel for this operation
1075 * @return 0, on success; negative error, otherwise
1077 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1078 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1080 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1081 const void *key, size_t key_sz,
1082 void *value, size_t value_sz, __u64 flags);
1085 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1086 * fetching next key that follows current key.
1087 * @param map BPF map to fetch next key from
1088 * @param cur_key pointer to memory containing bytes of current key or NULL to
1089 * fetch the first key
1090 * @param next_key pointer to memory to write next key into
1091 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1092 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1093 * negative error, otherwise
1095 * **bpf_map__get_next_key()** is high-level equivalent of
1096 * **bpf_map_get_next_key()** API with added check for key size.
1098 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1099 const void *cur_key, void *next_key, size_t key_sz);
1101 struct bpf_xdp_set_link_opts {
1106 #define bpf_xdp_set_link_opts__last_field old_fd
1108 struct bpf_xdp_attach_opts {
1113 #define bpf_xdp_attach_opts__last_field old_prog_fd
1115 struct bpf_xdp_query_opts {
1117 __u32 prog_id; /* output */
1118 __u32 drv_prog_id; /* output */
1119 __u32 hw_prog_id; /* output */
1120 __u32 skb_prog_id; /* output */
1121 __u8 attach_mode; /* output */
1122 __u64 feature_flags; /* output */
1123 __u32 xdp_zc_max_segs; /* output */
1126 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1128 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1129 const struct bpf_xdp_attach_opts *opts);
1130 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1131 const struct bpf_xdp_attach_opts *opts);
1132 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1133 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1135 /* TC related API */
1136 enum bpf_tc_attach_point {
1137 BPF_TC_INGRESS = 1 << 0,
1138 BPF_TC_EGRESS = 1 << 1,
1139 BPF_TC_CUSTOM = 1 << 2,
1142 #define BPF_TC_PARENT(a, b) \
1143 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1146 BPF_TC_F_REPLACE = 1 << 0,
1149 struct bpf_tc_hook {
1152 enum bpf_tc_attach_point attach_point;
1156 #define bpf_tc_hook__last_field parent
1158 struct bpf_tc_opts {
1167 #define bpf_tc_opts__last_field priority
1169 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1170 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1171 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1172 struct bpf_tc_opts *opts);
1173 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1174 const struct bpf_tc_opts *opts);
1175 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1176 struct bpf_tc_opts *opts);
1178 /* Ring buffer APIs */
1180 struct user_ring_buffer;
1182 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1184 struct ring_buffer_opts {
1185 size_t sz; /* size of this struct, for forward/backward compatibility */
1188 #define ring_buffer_opts__last_field sz
1190 LIBBPF_API struct ring_buffer *
1191 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1192 const struct ring_buffer_opts *opts);
1193 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1194 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1195 ring_buffer_sample_fn sample_cb, void *ctx);
1196 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1197 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1198 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1200 struct user_ring_buffer_opts {
1201 size_t sz; /* size of this struct, for forward/backward compatibility */
1204 #define user_ring_buffer_opts__last_field sz
1207 * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1210 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1211 * @param opts Options for how the ring buffer should be created.
1212 * @return A user ring buffer on success; NULL and errno being set on a
1215 LIBBPF_API struct user_ring_buffer *
1216 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1219 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1221 * @param rb A pointer to a user ring buffer.
1222 * @param size The size of the sample, in bytes.
1223 * @return A pointer to an 8-byte aligned reserved region of the user ring
1224 * buffer; NULL, and errno being set if a sample could not be reserved.
1226 * This function is *not* thread safe, and callers must synchronize accessing
1227 * this function if there are multiple producers. If a size is requested that
1228 * is larger than the size of the entire ring buffer, errno will be set to
1229 * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1230 * but currently does not have enough space, errno is set to ENOSPC and NULL is
1233 * After initializing the sample, callers must invoke
1234 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1235 * the sample must be freed with **user_ring_buffer__discard()**.
1237 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1240 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1241 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1243 * @param rb The user ring buffer.
1244 * @param size The size of the sample, in bytes.
1245 * @param timeout_ms The amount of time, in milliseconds, for which the caller
1246 * should block when waiting for a sample. -1 causes the caller to block
1248 * @return A pointer to an 8-byte aligned reserved region of the user ring
1249 * buffer; NULL, and errno being set if a sample could not be reserved.
1251 * This function is *not* thread safe, and callers must synchronize
1252 * accessing this function if there are multiple producers
1254 * If **timeout_ms** is -1, the function will block indefinitely until a sample
1255 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1256 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1257 * will occur and the function will return immediately after attempting to
1260 * If **size** is larger than the size of the entire ring buffer, errno is set
1261 * to E2BIG and NULL is returned. If the ring buffer could accommodate
1262 * **size**, but currently does not have enough space, the caller will block
1263 * until at most **timeout_ms** has elapsed. If insufficient space is available
1264 * at that time, errno is set to ENOSPC, and NULL is returned.
1266 * The kernel guarantees that it will wake up this thread to check if
1267 * sufficient space is available in the ring buffer at least once per
1268 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1269 * least one sample is consumed, and the BPF program did not invoke the
1270 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1271 * kernel does not guarantee this. If the helper function is invoked with
1272 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1275 * When a sample of size **size** is found within **timeout_ms**, a pointer to
1276 * the sample is returned. After initializing the sample, callers must invoke
1277 * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1278 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1280 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1285 * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1286 * into the ring buffer.
1287 * @param rb The user ring buffer.
1288 * @param sample A reserved sample.
1290 * It is not necessary to synchronize amongst multiple producers when invoking
1293 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1296 * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1297 * @param rb The user ring buffer.
1298 * @param sample A reserved sample.
1300 * It is not necessary to synchronize amongst multiple producers when invoking
1303 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1306 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1307 * created with **user_ring_buffer__new()**.
1308 * @param rb The user ring buffer being freed.
1310 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1312 /* Perf buffer APIs */
1315 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1316 void *data, __u32 size);
1317 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1319 /* common use perf buffer options */
1320 struct perf_buffer_opts {
1322 __u32 sample_period;
1325 #define perf_buffer_opts__last_field sample_period
1328 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1329 * BPF_PERF_EVENT_ARRAY map
1330 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1331 * code to send data over to user-space
1332 * @param page_cnt number of memory pages allocated for each per-CPU buffer
1333 * @param sample_cb function called on each received data record
1334 * @param lost_cb function called when record loss has occurred
1335 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1336 * @return a new instance of struct perf_buffer on success, NULL on error with
1337 * *errno* containing an error code
1339 LIBBPF_API struct perf_buffer *
1340 perf_buffer__new(int map_fd, size_t page_cnt,
1341 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1342 const struct perf_buffer_opts *opts);
1344 enum bpf_perf_event_ret {
1345 LIBBPF_PERF_EVENT_DONE = 0,
1346 LIBBPF_PERF_EVENT_ERROR = -1,
1347 LIBBPF_PERF_EVENT_CONT = -2,
1350 struct perf_event_header;
1352 typedef enum bpf_perf_event_ret
1353 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1355 /* raw perf buffer options, giving most power and control */
1356 struct perf_buffer_raw_opts {
1360 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1361 * max_entries of given PERF_EVENT_ARRAY map)
1364 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1366 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1369 #define perf_buffer_raw_opts__last_field map_keys
1371 struct perf_event_attr;
1373 LIBBPF_API struct perf_buffer *
1374 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1375 perf_buffer_event_fn event_cb, void *ctx,
1376 const struct perf_buffer_raw_opts *opts);
1378 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1379 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1380 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1381 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1382 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1383 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1384 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1386 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1387 * memory region of the ring buffer.
1388 * This ring buffer can be used to implement a custom events consumer.
1389 * The ring buffer starts with the *struct perf_event_mmap_page*, which
1390 * holds the ring buffer managment fields, when accessing the header
1391 * structure it's important to be SMP aware.
1392 * You can refer to *perf_event_read_simple* for a simple example.
1393 * @param pb the perf buffer structure
1394 * @param buf_idx the buffer index to retreive
1395 * @param buf (out) gets the base pointer of the mmap()'ed memory
1396 * @param buf_size (out) gets the size of the mmap()'ed region
1397 * @return 0 on success, negative error code for failure
1399 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1402 struct bpf_prog_linfo;
1403 struct bpf_prog_info;
1405 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1406 LIBBPF_API struct bpf_prog_linfo *
1407 bpf_prog_linfo__new(const struct bpf_prog_info *info);
1408 LIBBPF_API const struct bpf_line_info *
1409 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1410 __u64 addr, __u32 func_idx, __u32 nr_skip);
1411 LIBBPF_API const struct bpf_line_info *
1412 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1413 __u32 insn_off, __u32 nr_skip);
1416 * Probe for supported system features
1418 * Note that running many of these probes in a short amount of time can cause
1419 * the kernel to reach the maximal size of lockable memory allowed for the
1420 * user, causing subsequent probes to fail. In this case, the caller may want
1421 * to adjust that limit with setrlimit().
1425 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1426 * BPF programs of a given type.
1427 * @param prog_type BPF program type to detect kernel support for
1428 * @param opts reserved for future extensibility, should be NULL
1429 * @return 1, if given program type is supported; 0, if given program type is
1430 * not supported; negative error code if feature detection failed or can't be
1433 * Make sure the process has required set of CAP_* permissions (or runs as
1434 * root) when performing feature checking.
1436 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1438 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1439 * BPF maps of a given type.
1440 * @param map_type BPF map type to detect kernel support for
1441 * @param opts reserved for future extensibility, should be NULL
1442 * @return 1, if given map type is supported; 0, if given map type is
1443 * not supported; negative error code if feature detection failed or can't be
1446 * Make sure the process has required set of CAP_* permissions (or runs as
1447 * root) when performing feature checking.
1449 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1451 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1452 * use of a given BPF helper from specified BPF program type.
1453 * @param prog_type BPF program type used to check the support of BPF helper
1454 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1455 * @param opts reserved for future extensibility, should be NULL
1456 * @return 1, if given combination of program type and helper is supported; 0,
1457 * if the combination is not supported; negative error code if feature
1458 * detection for provided input arguments failed or can't be performed
1460 * Make sure the process has required set of CAP_* permissions (or runs as
1461 * root) when performing feature checking.
1463 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1464 enum bpf_func_id helper_id, const void *opts);
1467 * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1468 * number of possible CPUs that the host kernel supports and expects.
1469 * @return number of possible CPUs; or error code on failure
1473 * int ncpus = libbpf_num_possible_cpus();
1477 * long values[ncpus];
1478 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1480 LIBBPF_API int libbpf_num_possible_cpus(void);
1482 struct bpf_map_skeleton {
1484 struct bpf_map **map;
1488 struct bpf_prog_skeleton {
1490 struct bpf_program **prog;
1491 struct bpf_link **link;
1494 struct bpf_object_skeleton {
1495 size_t sz; /* size of this struct, for forward/backward compatibility */
1501 struct bpf_object **obj;
1504 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1505 struct bpf_map_skeleton *maps;
1508 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1509 struct bpf_prog_skeleton *progs;
1513 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1514 const struct bpf_object_open_opts *opts);
1515 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1516 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1517 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1518 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1520 struct bpf_var_skeleton {
1522 struct bpf_map **map;
1526 struct bpf_object_subskeleton {
1527 size_t sz; /* size of this struct, for forward/backward compatibility */
1529 const struct bpf_object *obj;
1532 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1533 struct bpf_map_skeleton *maps;
1536 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1537 struct bpf_prog_skeleton *progs;
1540 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1541 struct bpf_var_skeleton *vars;
1545 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1547 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1549 struct gen_loader_opts {
1550 size_t sz; /* size of this struct, for forward/backward compatibility */
1557 #define gen_loader_opts__last_field insns_sz
1558 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1559 struct gen_loader_opts *opts);
1561 enum libbpf_tristate {
1567 struct bpf_linker_opts {
1568 /* size of this struct, for forward/backward compatibility */
1571 #define bpf_linker_opts__last_field sz
1573 struct bpf_linker_file_opts {
1574 /* size of this struct, for forward/backward compatibility */
1577 #define bpf_linker_file_opts__last_field sz
1581 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1582 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1583 const char *filename,
1584 const struct bpf_linker_file_opts *opts);
1585 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1586 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1589 * Custom handling of BPF program's SEC() definitions
1592 struct bpf_prog_load_opts; /* defined in bpf.h */
1594 /* Called during bpf_object__open() for each recognized BPF program. Callback
1595 * can use various bpf_program__set_*() setters to adjust whatever properties
1598 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1600 /* Called right before libbpf performs bpf_prog_load() to load BPF program
1601 * into the kernel. Callback can adjust opts as necessary.
1603 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1604 struct bpf_prog_load_opts *opts, long cookie);
1606 /* Called during skeleton attach or through bpf_program__attach(). If
1607 * auto-attach is not supported, callback should return 0 and set link to
1608 * NULL (it's not considered an error during skeleton attach, but it will be
1609 * an error for bpf_program__attach() calls). On error, error should be
1610 * returned directly and link set to NULL. On success, return 0 and set link
1611 * to a valid struct bpf_link.
1613 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1614 struct bpf_link **link);
1616 struct libbpf_prog_handler_opts {
1617 /* size of this struct, for forward/backward compatibility */
1619 /* User-provided value that is passed to prog_setup_fn,
1620 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1621 * register one set of callbacks for multiple SEC() definitions and
1622 * still be able to distinguish them, if necessary. For example,
1623 * libbpf itself is using this to pass necessary flags (e.g.,
1624 * sleepable flag) to a common internal SEC() handler.
1627 /* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1628 * Callback is optional, pass NULL if it's not necessary.
1630 libbpf_prog_setup_fn_t prog_setup_fn;
1631 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1632 * Callback is optional, pass NULL if it's not necessary.
1634 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1635 /* BPF program attach callback (see libbpf_prog_attach_fn_t).
1636 * Callback is optional, pass NULL if it's not necessary.
1638 libbpf_prog_attach_fn_t prog_attach_fn;
1640 #define libbpf_prog_handler_opts__last_field prog_attach_fn
1643 * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1645 * @param sec section prefix for which custom handler is registered
1646 * @param prog_type BPF program type associated with specified section
1647 * @param exp_attach_type Expected BPF attach type associated with specified section
1648 * @param opts optional cookie, callbacks, and other extra options
1649 * @return Non-negative handler ID is returned on success. This handler ID has
1650 * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1651 * custom handler. Negative error code is returned on error.
1653 * *sec* defines which SEC() definitions are handled by this custom handler
1654 * registration. *sec* can have few different forms:
1655 * - if *sec* is just a plain string (e.g., "abc"), it will match only
1656 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1658 * - if *sec* is of the form "abc/", proper SEC() form is
1659 * SEC("abc/something"), where acceptable "something" should be checked by
1660 * *prog_init_fn* callback, if there are additional restrictions;
1661 * - if *sec* is of the form "abc+", it will successfully match both
1662 * SEC("abc") and SEC("abc/whatever") forms;
1663 * - if *sec* is NULL, custom handler is registered for any BPF program that
1664 * doesn't match any of the registered (custom or libbpf's own) SEC()
1665 * handlers. There could be only one such generic custom handler registered
1666 * at any given time.
1668 * All custom handlers (except the one with *sec* == NULL) are processed
1669 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1670 * SEC() handlers by registering custom ones for the same section prefix
1671 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1674 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1675 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1676 * to ensure synchronization if there is a risk of running this API from
1677 * multiple threads simultaneously.
1679 LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1680 enum bpf_prog_type prog_type,
1681 enum bpf_attach_type exp_attach_type,
1682 const struct libbpf_prog_handler_opts *opts);
1684 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1685 * custom BPF program SEC() handler.
1686 * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1687 * after successful registration
1688 * @return 0 on success, negative error code if handler isn't found
1690 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1691 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1692 * to ensure synchronization if there is a risk of running this API from
1693 * multiple threads simultaneously.
1695 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1701 #endif /* __LIBBPF_LIBBPF_H */