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);
269 LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path);
271 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
272 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
273 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
276 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
277 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
279 LIBBPF_API struct bpf_program *
280 bpf_object__find_program_by_name(const struct bpf_object *obj,
284 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
285 enum bpf_attach_type *expected_attach_type);
286 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
287 enum bpf_attach_type *attach_type);
288 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
289 enum bpf_attach_type attach_type);
291 /* Accessors of bpf_program */
294 LIBBPF_API struct bpf_program *
295 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
297 #define bpf_object__for_each_program(pos, obj) \
298 for ((pos) = bpf_object__next_program((obj), NULL); \
300 (pos) = bpf_object__next_program((obj), (pos)))
302 LIBBPF_API struct bpf_program *
303 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
305 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
308 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
309 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
310 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
311 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
312 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
313 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
318 * @brief **bpf_program__insns()** gives read-only access to BPF program's
319 * underlying BPF instructions.
320 * @param prog BPF program for which to return instructions
321 * @return a pointer to an array of BPF instructions that belong to the
322 * specified BPF program
324 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
325 * pointed to can be fetched using **bpf_program__insn_cnt()** API.
327 * Keep in mind, libbpf can modify and append/delete BPF program's
328 * instructions as it processes BPF object file and prepares everything for
329 * uploading into the kernel. So depending on the point in BPF object
330 * lifetime, **bpf_program__insns()** can return different sets of
331 * instructions. As an example, during BPF object load phase BPF program
332 * instructions will be CO-RE-relocated, BPF subprograms instructions will be
333 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
334 * returned before **bpf_object__load()** and after it might be quite
337 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
340 * @brief **bpf_program__set_insns()** can set BPF program's underlying
343 * WARNING: This is a very advanced libbpf API and users need to know
344 * what they are doing. This should be used from prog_prepare_load_fn
347 * @param prog BPF program for which to return instructions
348 * @param new_insns a pointer to an array of BPF instructions
349 * @param new_insn_cnt number of `struct bpf_insn`'s that form
350 * specified BPF program
351 * @return 0, on success; negative error code, otherwise
353 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
354 struct bpf_insn *new_insns, size_t new_insn_cnt);
357 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
358 * that form specified BPF program.
359 * @param prog BPF program for which to return number of BPF instructions
361 * See **bpf_program__insns()** documentation for notes on how libbpf can
362 * change instructions and their count during different phases of
363 * **bpf_object** lifetime.
365 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
367 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
370 * @brief **bpf_program__pin()** pins the BPF program to a file
371 * in the BPF FS specified by a path. This increments the programs
372 * reference count, allowing it to stay loaded after the process
373 * which loaded it has exited.
375 * @param prog BPF program to pin, must already be loaded
376 * @param path file path in a BPF file system
377 * @return 0, on success; negative error code, otherwise
379 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
382 * @brief **bpf_program__unpin()** unpins the BPF program from a file
383 * in the BPFFS specified by a path. This decrements the programs
386 * The file pinning the BPF program can also be unlinked by a different
387 * process in which case this function will return an error.
389 * @param prog BPF program to unpin
390 * @param path file path to the pin in a BPF file system
391 * @return 0, on success; negative error code, otherwise
393 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
394 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
398 LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
399 LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
400 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
402 * @brief **bpf_link__pin()** pins the BPF link to a file
403 * in the BPF FS specified by a path. This increments the links
404 * reference count, allowing it to stay loaded after the process
405 * which loaded it has exited.
407 * @param link BPF link to pin, must already be loaded
408 * @param path file path in a BPF file system
409 * @return 0, on success; negative error code, otherwise
412 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
415 * @brief **bpf_link__unpin()** unpins the BPF link from a file
416 * in the BPFFS specified by a path. This decrements the links
419 * The file pinning the BPF link can also be unlinked by a different
420 * process in which case this function will return an error.
422 * @param prog BPF program to unpin
423 * @param path file path to the pin in a BPF file system
424 * @return 0, on success; negative error code, otherwise
426 LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
427 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
428 struct bpf_program *prog);
429 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
430 LIBBPF_API int bpf_link__detach(struct bpf_link *link);
431 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
434 * @brief **bpf_program__attach()** is a generic function for attaching
435 * a BPF program based on auto-detection of program type, attach type,
436 * and extra paremeters, where applicable.
438 * @param prog BPF program to attach
439 * @return Reference to the newly created BPF link; or NULL is returned on error,
440 * error code is stored in errno
442 * This is supported for:
443 * - kprobe/kretprobe (depends on SEC() definition)
444 * - uprobe/uretprobe (depends on SEC() definition)
447 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
449 LIBBPF_API struct bpf_link *
450 bpf_program__attach(const struct bpf_program *prog);
452 struct bpf_perf_event_opts {
453 /* size of this struct, for forward/backward compatibility */
455 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
457 /* don't use BPF link when attach BPF program */
458 bool force_ioctl_attach;
461 #define bpf_perf_event_opts__last_field force_ioctl_attach
463 LIBBPF_API struct bpf_link *
464 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
466 LIBBPF_API struct bpf_link *
467 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
468 const struct bpf_perf_event_opts *opts);
471 * enum probe_attach_mode - the mode to attach kprobe/uprobe
473 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will
474 * be returned if it is not supported by the kernel.
476 enum probe_attach_mode {
477 /* attach probe in latest supported mode by kernel */
478 PROBE_ATTACH_MODE_DEFAULT = 0,
479 /* attach probe in legacy mode, using debugfs/tracefs */
480 PROBE_ATTACH_MODE_LEGACY,
481 /* create perf event with perf_event_open() syscall */
482 PROBE_ATTACH_MODE_PERF,
483 /* attach probe with BPF link */
484 PROBE_ATTACH_MODE_LINK,
487 struct bpf_kprobe_opts {
488 /* size of this struct, for forward/backward compatibility */
490 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
492 /* function's offset to install kprobe to */
494 /* kprobe is return probe */
496 /* kprobe attach mode */
497 enum probe_attach_mode attach_mode;
500 #define bpf_kprobe_opts__last_field attach_mode
502 LIBBPF_API struct bpf_link *
503 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
504 const char *func_name);
505 LIBBPF_API struct bpf_link *
506 bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
507 const char *func_name,
508 const struct bpf_kprobe_opts *opts);
510 struct bpf_kprobe_multi_opts {
511 /* size of this struct, for forward/backward compatibility */
513 /* array of function symbols to attach */
515 /* array of function addresses to attach */
516 const unsigned long *addrs;
517 /* array of user-provided values fetchable through bpf_get_attach_cookie */
518 const __u64 *cookies;
519 /* number of elements in syms/addrs/cookies arrays */
521 /* create return kprobes */
526 #define bpf_kprobe_multi_opts__last_field retprobe
528 LIBBPF_API struct bpf_link *
529 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
531 const struct bpf_kprobe_multi_opts *opts);
533 struct bpf_uprobe_multi_opts {
534 /* size of this struct, for forward/backward compatibility */
536 /* array of function symbols to attach to */
538 /* array of function addresses to attach to */
539 const unsigned long *offsets;
540 /* optional, array of associated ref counter offsets */
541 const unsigned long *ref_ctr_offsets;
542 /* optional, array of associated BPF cookies */
543 const __u64 *cookies;
544 /* number of elements in syms/addrs/cookies arrays */
546 /* create return uprobes */
551 #define bpf_uprobe_multi_opts__last_field retprobe
554 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
555 * to multiple uprobes with uprobe_multi link.
557 * User can specify 2 mutually exclusive set of inputs:
559 * 1) use only path/func_pattern/pid arguments
561 * 2) use path/pid with allowed combinations of
562 * syms/offsets/ref_ctr_offsets/cookies/cnt
564 * - syms and offsets are mutually exclusive
565 * - ref_ctr_offsets and cookies are optional
568 * @param prog BPF program to attach
569 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
570 * -1 for all processes
571 * @param binary_path Path to binary
572 * @param func_pattern Regular expression to specify functions to attach
574 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
575 * @return 0, on success; negative error code, otherwise
577 LIBBPF_API struct bpf_link *
578 bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
580 const char *binary_path,
581 const char *func_pattern,
582 const struct bpf_uprobe_multi_opts *opts);
584 struct bpf_ksyscall_opts {
585 /* size of this struct, for forward/backward compatibility */
587 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
589 /* attach as return probe? */
593 #define bpf_ksyscall_opts__last_field retprobe
596 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
597 * to kernel syscall handler of a specified syscall. Optionally it's possible
598 * to request to install retprobe that will be triggered at syscall exit. It's
599 * also possible to associate BPF cookie (though options).
601 * Libbpf automatically will determine correct full kernel function name,
602 * which depending on system architecture and kernel version/configuration
603 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
604 * attach specified program using kprobe/kretprobe mechanism.
606 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
607 * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
609 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
610 * not handle all the calling convention quirks for mmap(), clone() and compat
611 * syscalls. It also only attaches to "native" syscall interfaces. If host
612 * system supports compat syscalls or defines 32-bit syscalls in 64-bit
613 * kernel, such syscall interfaces won't be attached to by libbpf.
615 * These limitations may or may not change in the future. Therefore it is
616 * recommended to use SEC("kprobe") for these syscalls or if working with
617 * compat and 32-bit interfaces is required.
619 * @param prog BPF program to attach
620 * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
621 * @param opts Additional options (see **struct bpf_ksyscall_opts**)
622 * @return Reference to the newly created BPF link; or NULL is returned on
623 * error, error code is stored in errno
625 LIBBPF_API struct bpf_link *
626 bpf_program__attach_ksyscall(const struct bpf_program *prog,
627 const char *syscall_name,
628 const struct bpf_ksyscall_opts *opts);
630 struct bpf_uprobe_opts {
631 /* size of this struct, for forward/backward compatibility */
633 /* offset of kernel reference counted USDT semaphore, added in
634 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
636 size_t ref_ctr_offset;
637 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
639 /* uprobe is return probe, invoked at function return time */
641 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified
642 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while
643 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an
644 * offset within a function, specify func_name and use func_offset argument to specify
645 * offset within the function. Shared library functions must specify the shared library
648 const char *func_name;
649 /* uprobe attach mode */
650 enum probe_attach_mode attach_mode;
653 #define bpf_uprobe_opts__last_field attach_mode
656 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
657 * to the userspace function which is found by binary path and
658 * offset. You can optionally specify a particular proccess to attach
659 * to. You can also optionally attach the program to the function
660 * exit instead of entry.
662 * @param prog BPF program to attach
663 * @param retprobe Attach to function exit
664 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
665 * -1 for all processes
666 * @param binary_path Path to binary that contains the function symbol
667 * @param func_offset Offset within the binary of the function symbol
668 * @return Reference to the newly created BPF link; or NULL is returned on error,
669 * error code is stored in errno
671 LIBBPF_API struct bpf_link *
672 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
673 pid_t pid, const char *binary_path,
677 * @brief **bpf_program__attach_uprobe_opts()** is just like
678 * bpf_program__attach_uprobe() except with a options struct
679 * for various configurations.
681 * @param prog BPF program to attach
682 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
683 * -1 for all processes
684 * @param binary_path Path to binary that contains the function symbol
685 * @param func_offset Offset within the binary of the function symbol
686 * @param opts Options for altering program attachment
687 * @return Reference to the newly created BPF link; or NULL is returned on error,
688 * error code is stored in errno
690 LIBBPF_API struct bpf_link *
691 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
692 const char *binary_path, size_t func_offset,
693 const struct bpf_uprobe_opts *opts);
695 struct bpf_usdt_opts {
696 /* size of this struct, for forward/backward compatibility */
698 /* custom user-provided value accessible through usdt_cookie() */
702 #define bpf_usdt_opts__last_field usdt_cookie
705 * @brief **bpf_program__attach_usdt()** is just like
706 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
707 * Statically Defined Tracepoint) attachment, instead of attaching to
708 * user-space function entry or exit.
710 * @param prog BPF program to attach
711 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
712 * -1 for all processes
713 * @param binary_path Path to binary that contains provided USDT probe
714 * @param usdt_provider USDT provider name
715 * @param usdt_name USDT probe name
716 * @param opts Options for altering program attachment
717 * @return Reference to the newly created BPF link; or NULL is returned on error,
718 * error code is stored in errno
720 LIBBPF_API struct bpf_link *
721 bpf_program__attach_usdt(const struct bpf_program *prog,
722 pid_t pid, const char *binary_path,
723 const char *usdt_provider, const char *usdt_name,
724 const struct bpf_usdt_opts *opts);
726 struct bpf_tracepoint_opts {
727 /* size of this struct, for forward/backward compatibility */
729 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
732 #define bpf_tracepoint_opts__last_field bpf_cookie
734 LIBBPF_API struct bpf_link *
735 bpf_program__attach_tracepoint(const struct bpf_program *prog,
736 const char *tp_category,
737 const char *tp_name);
738 LIBBPF_API struct bpf_link *
739 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
740 const char *tp_category,
742 const struct bpf_tracepoint_opts *opts);
744 LIBBPF_API struct bpf_link *
745 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
746 const char *tp_name);
748 struct bpf_trace_opts {
749 /* size of this struct, for forward/backward compatibility */
751 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
754 #define bpf_trace_opts__last_field cookie
756 LIBBPF_API struct bpf_link *
757 bpf_program__attach_trace(const struct bpf_program *prog);
758 LIBBPF_API struct bpf_link *
759 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
761 LIBBPF_API struct bpf_link *
762 bpf_program__attach_lsm(const struct bpf_program *prog);
763 LIBBPF_API struct bpf_link *
764 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
765 LIBBPF_API struct bpf_link *
766 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
767 LIBBPF_API struct bpf_link *
768 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
769 LIBBPF_API struct bpf_link *
770 bpf_program__attach_freplace(const struct bpf_program *prog,
771 int target_fd, const char *attach_func_name);
773 struct bpf_netfilter_opts {
774 /* size of this struct, for forward/backward compatibility */
782 #define bpf_netfilter_opts__last_field flags
784 LIBBPF_API struct bpf_link *
785 bpf_program__attach_netfilter(const struct bpf_program *prog,
786 const struct bpf_netfilter_opts *opts);
788 struct bpf_tcx_opts {
789 /* size of this struct, for forward/backward compatibility */
794 __u64 expected_revision;
797 #define bpf_tcx_opts__last_field expected_revision
799 LIBBPF_API struct bpf_link *
800 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
801 const struct bpf_tcx_opts *opts);
803 struct bpf_netkit_opts {
804 /* size of this struct, for forward/backward compatibility */
809 __u64 expected_revision;
812 #define bpf_netkit_opts__last_field expected_revision
814 LIBBPF_API struct bpf_link *
815 bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
816 const struct bpf_netkit_opts *opts);
820 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
821 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
823 struct bpf_iter_attach_opts {
824 size_t sz; /* size of this struct for forward/backward compatibility */
825 union bpf_iter_link_info *link_info;
828 #define bpf_iter_attach_opts__last_field link_info_len
830 LIBBPF_API struct bpf_link *
831 bpf_program__attach_iter(const struct bpf_program *prog,
832 const struct bpf_iter_attach_opts *opts);
834 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
837 * @brief **bpf_program__set_type()** sets the program
838 * type of the passed BPF program.
839 * @param prog BPF program to set the program type for
840 * @param type program type to set the BPF map to have
841 * @return error code; or 0 if no error. An error occurs
842 * if the object is already loaded.
844 * This must be called before the BPF object is loaded,
845 * otherwise it has no effect and an error is returned.
847 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
848 enum bpf_prog_type type);
850 LIBBPF_API enum bpf_attach_type
851 bpf_program__expected_attach_type(const struct bpf_program *prog);
854 * @brief **bpf_program__set_expected_attach_type()** sets the
855 * attach type of the passed BPF program. This is used for
856 * auto-detection of attachment when programs are loaded.
857 * @param prog BPF program to set the attach type for
858 * @param type attach type to set the BPF map to have
859 * @return error code; or 0 if no error. An error occurs
860 * if the object is already loaded.
862 * This must be called before the BPF object is loaded,
863 * otherwise it has no effect and an error is returned.
866 bpf_program__set_expected_attach_type(struct bpf_program *prog,
867 enum bpf_attach_type type);
869 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
870 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
872 /* Per-program log level and log buffer getters/setters.
873 * See bpf_object_open_opts comments regarding log_level and log_buf
876 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
877 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
878 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
879 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
882 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
883 * for supported BPF program types:
884 * - BTF-aware raw tracepoints (tp_btf);
885 * - fentry/fexit/fmod_ret;
888 * @param prog BPF program to set the attach type for
889 * @param type attach type to set the BPF map to have
890 * @return error code; or 0 if no error occurred.
893 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
894 const char *attach_func_name);
897 * @brief **bpf_object__find_map_by_name()** returns BPF map of
898 * the given name, if it exists within the passed BPF object
899 * @param obj BPF object
900 * @param name name of the BPF map
901 * @return BPF map instance, if such map exists within the BPF object;
904 LIBBPF_API struct bpf_map *
905 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
908 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
910 LIBBPF_API struct bpf_map *
911 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
913 #define bpf_object__for_each_map(pos, obj) \
914 for ((pos) = bpf_object__next_map((obj), NULL); \
916 (pos) = bpf_object__next_map((obj), (pos)))
917 #define bpf_map__for_each bpf_object__for_each_map
919 LIBBPF_API struct bpf_map *
920 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
923 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
924 * BPF map during BPF object load phase.
925 * @param map the BPF map instance
926 * @param autocreate whether to create BPF map during BPF object load
927 * @return 0 on success; -EBUSY if BPF object was already loaded
929 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
930 * BPF map. By default, libbpf will attempt to create every single BPF map
931 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
932 * and fill in map FD in BPF instructions.
934 * This API allows to opt-out of this process for specific map instance. This
935 * can be useful if host kernel doesn't support such BPF map type or used
936 * combination of flags and user application wants to avoid creating such
937 * a map in the first place. User is still responsible to make sure that their
938 * BPF-side code that expects to use such missing BPF map is recognized by BPF
939 * verifier as dead code, otherwise BPF verifier will reject such BPF program.
941 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
942 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
945 * @brief **bpf_map__fd()** gets the file descriptor of the passed
947 * @param map the BPF map instance
948 * @return the file descriptor; or -EINVAL in case of an error
950 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
951 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
953 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
954 /* get/set map type */
955 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
956 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
957 /* get/set map size (max_entries) */
958 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
959 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
960 /* get/set map flags */
961 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
962 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
963 /* get/set map NUMA node */
964 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
965 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
966 /* get/set map key size */
967 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
968 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
969 /* get map value size */
970 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
972 * @brief **bpf_map__set_value_size()** sets map value size.
973 * @param map the BPF map instance
974 * @return 0, on success; negative error, otherwise
976 * There is a special case for maps with associated memory-mapped regions, like
977 * the global data section maps (bss, data, rodata). When this function is used
978 * on such a map, the mapped region is resized. Afterward, an attempt is made to
979 * adjust the corresponding BTF info. This attempt is best-effort and can only
980 * succeed if the last variable of the data section map is an array. The array
981 * BTF type is replaced by a new BTF array type with a different length.
982 * Any previously existing pointers returned from bpf_map__initial_value() or
983 * corresponding data section skeleton pointer must be reinitialized.
985 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
986 /* get map key/value BTF type IDs */
987 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
988 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
989 /* get/set map if_index */
990 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
991 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
992 /* get/set map map_extra flags */
993 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
994 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
996 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
997 const void *data, size_t size);
998 LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
1001 * @brief **bpf_map__is_internal()** tells the caller whether or not the
1002 * passed map is a special map created by libbpf automatically for things like
1003 * global variables, __ksym externs, Kconfig values, etc
1004 * @param map the bpf_map
1005 * @return true, if the map is an internal map; false, otherwise
1007 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
1010 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
1011 * BPF map should be pinned. This does not actually create the 'pin'.
1012 * @param map The bpf_map
1013 * @param path The path
1014 * @return 0, on success; negative error, otherwise
1016 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
1019 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
1020 * BPF map should be pinned.
1021 * @param map The bpf_map
1022 * @return The path string; which can be NULL
1024 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
1027 * @brief **bpf_map__is_pinned()** tells the caller whether or not the
1028 * passed map has been pinned via a 'pin' file.
1029 * @param map The bpf_map
1030 * @return true, if the map is pinned; false, otherwise
1032 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
1035 * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
1036 * for the BPF map. This increments the reference count on the
1037 * BPF map which will keep the BPF map loaded even after the
1038 * userspace process which loaded it has exited.
1039 * @param map The bpf_map to pin
1040 * @param path A file path for the 'pin'
1041 * @return 0, on success; negative error, otherwise
1043 * If `path` is NULL the maps `pin_path` attribute will be used. If this is
1044 * also NULL, an error will be returned and the map will not be pinned.
1046 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
1049 * @brief **bpf_map__unpin()** removes the file that serves as a
1050 * 'pin' for the BPF map.
1051 * @param map The bpf_map to unpin
1052 * @param path A file path for the 'pin'
1053 * @return 0, on success; negative error, otherwise
1055 * The `path` parameter can be NULL, in which case the `pin_path`
1056 * map attribute is unpinned. If both the `path` parameter and
1057 * `pin_path` map attribute are set, they must be equal.
1059 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
1061 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
1062 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
1065 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
1066 * corresponding to provided key.
1067 * @param map BPF map to lookup element in
1068 * @param key pointer to memory containing bytes of the key used for lookup
1069 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1070 * @param value pointer to memory in which looked up value will be stored
1071 * @param value_sz size in byte of value data memory; it has to match BPF map
1072 * definition's **value_size**. For per-CPU BPF maps value size has to be
1073 * a product of BPF map value size and number of possible CPUs in the system
1074 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1075 * per-CPU values value size has to be aligned up to closest 8 bytes for
1076 * alignment reasons, so expected size is: `round_up(value_size, 8)
1077 * * libbpf_num_possible_cpus()`.
1078 * @flags extra flags passed to kernel for this operation
1079 * @return 0, on success; negative error, otherwise
1081 * **bpf_map__lookup_elem()** is high-level equivalent of
1082 * **bpf_map_lookup_elem()** API with added check for key and value size.
1084 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1085 const void *key, size_t key_sz,
1086 void *value, size_t value_sz, __u64 flags);
1089 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1090 * map that corresponds to provided key.
1091 * @param map BPF map to insert to or update element in
1092 * @param key pointer to memory containing bytes of the key
1093 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1094 * @param value pointer to memory containing bytes of the value
1095 * @param value_sz size in byte of value data memory; it has to match BPF map
1096 * definition's **value_size**. For per-CPU BPF maps value size has to be
1097 * a product of BPF map value size and number of possible CPUs in the system
1098 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1099 * per-CPU values value size has to be aligned up to closest 8 bytes for
1100 * alignment reasons, so expected size is: `round_up(value_size, 8)
1101 * * libbpf_num_possible_cpus()`.
1102 * @flags extra flags passed to kernel for this operation
1103 * @return 0, on success; negative error, otherwise
1105 * **bpf_map__update_elem()** is high-level equivalent of
1106 * **bpf_map_update_elem()** API with added check for key and value size.
1108 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1109 const void *key, size_t key_sz,
1110 const void *value, size_t value_sz, __u64 flags);
1113 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1114 * corresponds to provided key.
1115 * @param map BPF map to delete element from
1116 * @param key pointer to memory containing bytes of the key
1117 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1118 * @flags extra flags passed to kernel for this operation
1119 * @return 0, on success; negative error, otherwise
1121 * **bpf_map__delete_elem()** is high-level equivalent of
1122 * **bpf_map_delete_elem()** API with added check for key size.
1124 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1125 const void *key, size_t key_sz, __u64 flags);
1128 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1129 * corresponding to provided key and atomically delete it afterwards.
1130 * @param map BPF map to lookup element in
1131 * @param key pointer to memory containing bytes of the key used for lookup
1132 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1133 * @param value pointer to memory in which looked up value will be stored
1134 * @param value_sz size in byte of value data memory; it has to match BPF map
1135 * definition's **value_size**. For per-CPU BPF maps value size has to be
1136 * a product of BPF map value size and number of possible CPUs in the system
1137 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1138 * per-CPU values value size has to be aligned up to closest 8 bytes for
1139 * alignment reasons, so expected size is: `round_up(value_size, 8)
1140 * * libbpf_num_possible_cpus()`.
1141 * @flags extra flags passed to kernel for this operation
1142 * @return 0, on success; negative error, otherwise
1144 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1145 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1147 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1148 const void *key, size_t key_sz,
1149 void *value, size_t value_sz, __u64 flags);
1152 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1153 * fetching next key that follows current key.
1154 * @param map BPF map to fetch next key from
1155 * @param cur_key pointer to memory containing bytes of current key or NULL to
1156 * fetch the first key
1157 * @param next_key pointer to memory to write next key into
1158 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1159 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1160 * negative error, otherwise
1162 * **bpf_map__get_next_key()** is high-level equivalent of
1163 * **bpf_map_get_next_key()** API with added check for key size.
1165 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1166 const void *cur_key, void *next_key, size_t key_sz);
1168 struct bpf_xdp_set_link_opts {
1173 #define bpf_xdp_set_link_opts__last_field old_fd
1175 struct bpf_xdp_attach_opts {
1180 #define bpf_xdp_attach_opts__last_field old_prog_fd
1182 struct bpf_xdp_query_opts {
1184 __u32 prog_id; /* output */
1185 __u32 drv_prog_id; /* output */
1186 __u32 hw_prog_id; /* output */
1187 __u32 skb_prog_id; /* output */
1188 __u8 attach_mode; /* output */
1189 __u64 feature_flags; /* output */
1190 __u32 xdp_zc_max_segs; /* output */
1193 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1195 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1196 const struct bpf_xdp_attach_opts *opts);
1197 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1198 const struct bpf_xdp_attach_opts *opts);
1199 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1200 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1202 /* TC related API */
1203 enum bpf_tc_attach_point {
1204 BPF_TC_INGRESS = 1 << 0,
1205 BPF_TC_EGRESS = 1 << 1,
1206 BPF_TC_CUSTOM = 1 << 2,
1209 #define BPF_TC_PARENT(a, b) \
1210 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1213 BPF_TC_F_REPLACE = 1 << 0,
1216 struct bpf_tc_hook {
1219 enum bpf_tc_attach_point attach_point;
1223 #define bpf_tc_hook__last_field parent
1225 struct bpf_tc_opts {
1234 #define bpf_tc_opts__last_field priority
1236 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1237 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1238 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1239 struct bpf_tc_opts *opts);
1240 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1241 const struct bpf_tc_opts *opts);
1242 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1243 struct bpf_tc_opts *opts);
1245 /* Ring buffer APIs */
1248 struct user_ring_buffer;
1250 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1252 struct ring_buffer_opts {
1253 size_t sz; /* size of this struct, for forward/backward compatibility */
1256 #define ring_buffer_opts__last_field sz
1258 LIBBPF_API struct ring_buffer *
1259 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1260 const struct ring_buffer_opts *opts);
1261 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1262 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1263 ring_buffer_sample_fn sample_cb, void *ctx);
1264 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1265 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1266 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1269 * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given
1270 * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance.
1272 * @param rb A ringbuffer manager object.
1273 * @param idx An index into the ringbuffers contained within the ringbuffer
1274 * manager object. The index is 0-based and corresponds to the order in which
1275 * ring_buffer__add was called.
1276 * @return A ringbuffer object on success; NULL and errno set if the index is
1279 LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb,
1283 * @brief **ring__consumer_pos()** returns the current consumer position in the
1286 * @param r A ringbuffer object.
1287 * @return The current consumer position.
1289 LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r);
1292 * @brief **ring__producer_pos()** returns the current producer position in the
1295 * @param r A ringbuffer object.
1296 * @return The current producer position.
1298 LIBBPF_API unsigned long ring__producer_pos(const struct ring *r);
1301 * @brief **ring__avail_data_size()** returns the number of bytes in the
1302 * ringbuffer not yet consumed. This has no locking associated with it, so it
1303 * can be inaccurate if operations are ongoing while this is called. However, it
1304 * should still show the correct trend over the long-term.
1306 * @param r A ringbuffer object.
1307 * @return The number of bytes not yet consumed.
1309 LIBBPF_API size_t ring__avail_data_size(const struct ring *r);
1312 * @brief **ring__size()** returns the total size of the ringbuffer's map data
1313 * area (excluding special producer/consumer pages). Effectively this gives the
1314 * amount of usable bytes of data inside the ringbuffer.
1316 * @param r A ringbuffer object.
1317 * @return The total size of the ringbuffer map data area.
1319 LIBBPF_API size_t ring__size(const struct ring *r);
1322 * @brief **ring__map_fd()** returns the file descriptor underlying the given
1325 * @param r A ringbuffer object.
1326 * @return The underlying ringbuffer file descriptor
1328 LIBBPF_API int ring__map_fd(const struct ring *r);
1331 * @brief **ring__consume()** consumes available ringbuffer data without event
1334 * @param r A ringbuffer object.
1335 * @return The number of records consumed (or INT_MAX, whichever is less), or
1336 * a negative number if any of the callbacks return an error.
1338 LIBBPF_API int ring__consume(struct ring *r);
1340 struct user_ring_buffer_opts {
1341 size_t sz; /* size of this struct, for forward/backward compatibility */
1344 #define user_ring_buffer_opts__last_field sz
1347 * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1350 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1351 * @param opts Options for how the ring buffer should be created.
1352 * @return A user ring buffer on success; NULL and errno being set on a
1355 LIBBPF_API struct user_ring_buffer *
1356 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1359 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1361 * @param rb A pointer to a user ring buffer.
1362 * @param size The size of the sample, in bytes.
1363 * @return A pointer to an 8-byte aligned reserved region of the user ring
1364 * buffer; NULL, and errno being set if a sample could not be reserved.
1366 * This function is *not* thread safe, and callers must synchronize accessing
1367 * this function if there are multiple producers. If a size is requested that
1368 * is larger than the size of the entire ring buffer, errno will be set to
1369 * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1370 * but currently does not have enough space, errno is set to ENOSPC and NULL is
1373 * After initializing the sample, callers must invoke
1374 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1375 * the sample must be freed with **user_ring_buffer__discard()**.
1377 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1380 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1381 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1383 * @param rb The user ring buffer.
1384 * @param size The size of the sample, in bytes.
1385 * @param timeout_ms The amount of time, in milliseconds, for which the caller
1386 * should block when waiting for a sample. -1 causes the caller to block
1388 * @return A pointer to an 8-byte aligned reserved region of the user ring
1389 * buffer; NULL, and errno being set if a sample could not be reserved.
1391 * This function is *not* thread safe, and callers must synchronize
1392 * accessing this function if there are multiple producers
1394 * If **timeout_ms** is -1, the function will block indefinitely until a sample
1395 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1396 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1397 * will occur and the function will return immediately after attempting to
1400 * If **size** is larger than the size of the entire ring buffer, errno is set
1401 * to E2BIG and NULL is returned. If the ring buffer could accommodate
1402 * **size**, but currently does not have enough space, the caller will block
1403 * until at most **timeout_ms** has elapsed. If insufficient space is available
1404 * at that time, errno is set to ENOSPC, and NULL is returned.
1406 * The kernel guarantees that it will wake up this thread to check if
1407 * sufficient space is available in the ring buffer at least once per
1408 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1409 * least one sample is consumed, and the BPF program did not invoke the
1410 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1411 * kernel does not guarantee this. If the helper function is invoked with
1412 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1415 * When a sample of size **size** is found within **timeout_ms**, a pointer to
1416 * the sample is returned. After initializing the sample, callers must invoke
1417 * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1418 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1420 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1425 * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1426 * into the ring buffer.
1427 * @param rb The user ring buffer.
1428 * @param sample A reserved sample.
1430 * It is not necessary to synchronize amongst multiple producers when invoking
1433 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1436 * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1437 * @param rb The user ring buffer.
1438 * @param sample A reserved sample.
1440 * It is not necessary to synchronize amongst multiple producers when invoking
1443 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1446 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1447 * created with **user_ring_buffer__new()**.
1448 * @param rb The user ring buffer being freed.
1450 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1452 /* Perf buffer APIs */
1455 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1456 void *data, __u32 size);
1457 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1459 /* common use perf buffer options */
1460 struct perf_buffer_opts {
1462 __u32 sample_period;
1465 #define perf_buffer_opts__last_field sample_period
1468 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1469 * BPF_PERF_EVENT_ARRAY map
1470 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1471 * code to send data over to user-space
1472 * @param page_cnt number of memory pages allocated for each per-CPU buffer
1473 * @param sample_cb function called on each received data record
1474 * @param lost_cb function called when record loss has occurred
1475 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1476 * @return a new instance of struct perf_buffer on success, NULL on error with
1477 * *errno* containing an error code
1479 LIBBPF_API struct perf_buffer *
1480 perf_buffer__new(int map_fd, size_t page_cnt,
1481 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1482 const struct perf_buffer_opts *opts);
1484 enum bpf_perf_event_ret {
1485 LIBBPF_PERF_EVENT_DONE = 0,
1486 LIBBPF_PERF_EVENT_ERROR = -1,
1487 LIBBPF_PERF_EVENT_CONT = -2,
1490 struct perf_event_header;
1492 typedef enum bpf_perf_event_ret
1493 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1495 /* raw perf buffer options, giving most power and control */
1496 struct perf_buffer_raw_opts {
1500 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1501 * max_entries of given PERF_EVENT_ARRAY map)
1504 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1506 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1509 #define perf_buffer_raw_opts__last_field map_keys
1511 struct perf_event_attr;
1513 LIBBPF_API struct perf_buffer *
1514 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1515 perf_buffer_event_fn event_cb, void *ctx,
1516 const struct perf_buffer_raw_opts *opts);
1518 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1519 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1520 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1521 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1522 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1523 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1524 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1526 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1527 * memory region of the ring buffer.
1528 * This ring buffer can be used to implement a custom events consumer.
1529 * The ring buffer starts with the *struct perf_event_mmap_page*, which
1530 * holds the ring buffer managment fields, when accessing the header
1531 * structure it's important to be SMP aware.
1532 * You can refer to *perf_event_read_simple* for a simple example.
1533 * @param pb the perf buffer structure
1534 * @param buf_idx the buffer index to retreive
1535 * @param buf (out) gets the base pointer of the mmap()'ed memory
1536 * @param buf_size (out) gets the size of the mmap()'ed region
1537 * @return 0 on success, negative error code for failure
1539 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1542 struct bpf_prog_linfo;
1543 struct bpf_prog_info;
1545 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1546 LIBBPF_API struct bpf_prog_linfo *
1547 bpf_prog_linfo__new(const struct bpf_prog_info *info);
1548 LIBBPF_API const struct bpf_line_info *
1549 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1550 __u64 addr, __u32 func_idx, __u32 nr_skip);
1551 LIBBPF_API const struct bpf_line_info *
1552 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1553 __u32 insn_off, __u32 nr_skip);
1556 * Probe for supported system features
1558 * Note that running many of these probes in a short amount of time can cause
1559 * the kernel to reach the maximal size of lockable memory allowed for the
1560 * user, causing subsequent probes to fail. In this case, the caller may want
1561 * to adjust that limit with setrlimit().
1565 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1566 * BPF programs of a given type.
1567 * @param prog_type BPF program type to detect kernel support for
1568 * @param opts reserved for future extensibility, should be NULL
1569 * @return 1, if given program type is supported; 0, if given program type is
1570 * not supported; negative error code if feature detection failed or can't be
1573 * Make sure the process has required set of CAP_* permissions (or runs as
1574 * root) when performing feature checking.
1576 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1578 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1579 * BPF maps of a given type.
1580 * @param map_type BPF map type to detect kernel support for
1581 * @param opts reserved for future extensibility, should be NULL
1582 * @return 1, if given map type is supported; 0, if given map type is
1583 * not supported; negative error code if feature detection failed or can't be
1586 * Make sure the process has required set of CAP_* permissions (or runs as
1587 * root) when performing feature checking.
1589 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1591 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1592 * use of a given BPF helper from specified BPF program type.
1593 * @param prog_type BPF program type used to check the support of BPF helper
1594 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1595 * @param opts reserved for future extensibility, should be NULL
1596 * @return 1, if given combination of program type and helper is supported; 0,
1597 * if the combination is not supported; negative error code if feature
1598 * detection for provided input arguments failed or can't be performed
1600 * Make sure the process has required set of CAP_* permissions (or runs as
1601 * root) when performing feature checking.
1603 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1604 enum bpf_func_id helper_id, const void *opts);
1607 * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1608 * number of possible CPUs that the host kernel supports and expects.
1609 * @return number of possible CPUs; or error code on failure
1613 * int ncpus = libbpf_num_possible_cpus();
1617 * long values[ncpus];
1618 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1620 LIBBPF_API int libbpf_num_possible_cpus(void);
1622 struct bpf_map_skeleton {
1624 struct bpf_map **map;
1628 struct bpf_prog_skeleton {
1630 struct bpf_program **prog;
1631 struct bpf_link **link;
1634 struct bpf_object_skeleton {
1635 size_t sz; /* size of this struct, for forward/backward compatibility */
1641 struct bpf_object **obj;
1644 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1645 struct bpf_map_skeleton *maps;
1648 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1649 struct bpf_prog_skeleton *progs;
1653 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1654 const struct bpf_object_open_opts *opts);
1655 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1656 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1657 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1658 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1660 struct bpf_var_skeleton {
1662 struct bpf_map **map;
1666 struct bpf_object_subskeleton {
1667 size_t sz; /* size of this struct, for forward/backward compatibility */
1669 const struct bpf_object *obj;
1672 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1673 struct bpf_map_skeleton *maps;
1676 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1677 struct bpf_prog_skeleton *progs;
1680 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1681 struct bpf_var_skeleton *vars;
1685 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1687 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1689 struct gen_loader_opts {
1690 size_t sz; /* size of this struct, for forward/backward compatibility */
1697 #define gen_loader_opts__last_field insns_sz
1698 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1699 struct gen_loader_opts *opts);
1701 enum libbpf_tristate {
1707 struct bpf_linker_opts {
1708 /* size of this struct, for forward/backward compatibility */
1711 #define bpf_linker_opts__last_field sz
1713 struct bpf_linker_file_opts {
1714 /* size of this struct, for forward/backward compatibility */
1717 #define bpf_linker_file_opts__last_field sz
1721 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1722 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1723 const char *filename,
1724 const struct bpf_linker_file_opts *opts);
1725 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1726 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1729 * Custom handling of BPF program's SEC() definitions
1732 struct bpf_prog_load_opts; /* defined in bpf.h */
1734 /* Called during bpf_object__open() for each recognized BPF program. Callback
1735 * can use various bpf_program__set_*() setters to adjust whatever properties
1738 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1740 /* Called right before libbpf performs bpf_prog_load() to load BPF program
1741 * into the kernel. Callback can adjust opts as necessary.
1743 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1744 struct bpf_prog_load_opts *opts, long cookie);
1746 /* Called during skeleton attach or through bpf_program__attach(). If
1747 * auto-attach is not supported, callback should return 0 and set link to
1748 * NULL (it's not considered an error during skeleton attach, but it will be
1749 * an error for bpf_program__attach() calls). On error, error should be
1750 * returned directly and link set to NULL. On success, return 0 and set link
1751 * to a valid struct bpf_link.
1753 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1754 struct bpf_link **link);
1756 struct libbpf_prog_handler_opts {
1757 /* size of this struct, for forward/backward compatibility */
1759 /* User-provided value that is passed to prog_setup_fn,
1760 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1761 * register one set of callbacks for multiple SEC() definitions and
1762 * still be able to distinguish them, if necessary. For example,
1763 * libbpf itself is using this to pass necessary flags (e.g.,
1764 * sleepable flag) to a common internal SEC() handler.
1767 /* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1768 * Callback is optional, pass NULL if it's not necessary.
1770 libbpf_prog_setup_fn_t prog_setup_fn;
1771 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1772 * Callback is optional, pass NULL if it's not necessary.
1774 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1775 /* BPF program attach callback (see libbpf_prog_attach_fn_t).
1776 * Callback is optional, pass NULL if it's not necessary.
1778 libbpf_prog_attach_fn_t prog_attach_fn;
1780 #define libbpf_prog_handler_opts__last_field prog_attach_fn
1783 * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1785 * @param sec section prefix for which custom handler is registered
1786 * @param prog_type BPF program type associated with specified section
1787 * @param exp_attach_type Expected BPF attach type associated with specified section
1788 * @param opts optional cookie, callbacks, and other extra options
1789 * @return Non-negative handler ID is returned on success. This handler ID has
1790 * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1791 * custom handler. Negative error code is returned on error.
1793 * *sec* defines which SEC() definitions are handled by this custom handler
1794 * registration. *sec* can have few different forms:
1795 * - if *sec* is just a plain string (e.g., "abc"), it will match only
1796 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1798 * - if *sec* is of the form "abc/", proper SEC() form is
1799 * SEC("abc/something"), where acceptable "something" should be checked by
1800 * *prog_init_fn* callback, if there are additional restrictions;
1801 * - if *sec* is of the form "abc+", it will successfully match both
1802 * SEC("abc") and SEC("abc/whatever") forms;
1803 * - if *sec* is NULL, custom handler is registered for any BPF program that
1804 * doesn't match any of the registered (custom or libbpf's own) SEC()
1805 * handlers. There could be only one such generic custom handler registered
1806 * at any given time.
1808 * All custom handlers (except the one with *sec* == NULL) are processed
1809 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1810 * SEC() handlers by registering custom ones for the same section prefix
1811 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1814 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1815 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1816 * to ensure synchronization if there is a risk of running this API from
1817 * multiple threads simultaneously.
1819 LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1820 enum bpf_prog_type prog_type,
1821 enum bpf_attach_type exp_attach_type,
1822 const struct libbpf_prog_handler_opts *opts);
1824 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1825 * custom BPF program SEC() handler.
1826 * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1827 * after successful registration
1828 * @return 0 on success, negative error code if handler isn't found
1830 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1831 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1832 * to ensure synchronization if there is a risk of running this API from
1833 * multiple threads simultaneously.
1835 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1841 #endif /* __LIBBPF_LIBBPF_H */