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1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3/*
4 * Common eBPF ELF object loading operations.
5 *
6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
8 * Copyright (C) 2015 Huawei Inc.
9 */
10#ifndef __LIBBPF_LIBBPF_H
11#define __LIBBPF_LIBBPF_H
12
13#include <stdarg.h>
14#include <stdio.h>
15#include <stdint.h>
16#include <stdbool.h>
17#include <sys/types.h> // for size_t
18#include <linux/bpf.h>
19
20#include "libbpf_common.h"
21#include "libbpf_legacy.h"
22
23#ifdef __cplusplus
24extern "C" {
25#endif
26
27LIBBPF_API __u32 libbpf_major_version(void);
28LIBBPF_API __u32 libbpf_minor_version(void);
29LIBBPF_API const char *libbpf_version_string(void);
30
31enum libbpf_errno {
32 __LIBBPF_ERRNO__START = 4000,
33
34 /* Something wrong in libelf */
35 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
36 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
37 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
38 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
39 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
40 LIBBPF_ERRNO__RELOC, /* Relocation failed */
41 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
42 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
43 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
44 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
45 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
46 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
47 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
48 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */
49 __LIBBPF_ERRNO__END,
50};
51
52LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
53
54/**
55 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type
56 * value into a textual representation.
57 * @param t The attach type.
58 * @return Pointer to a static string identifying the attach type. NULL is
59 * returned for unknown **bpf_attach_type** values.
60 */
61LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t);
62
63/**
64 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value
65 * into a textual representation.
66 * @param t The link type.
67 * @return Pointer to a static string identifying the link type. NULL is
68 * returned for unknown **bpf_link_type** values.
69 */
70LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t);
71
72/**
73 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value
74 * into a textual representation.
75 * @param t The map type.
76 * @return Pointer to a static string identifying the map type. NULL is
77 * returned for unknown **bpf_map_type** values.
78 */
79LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t);
80
81/**
82 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type
83 * value into a textual representation.
84 * @param t The program type.
85 * @return Pointer to a static string identifying the program type. NULL is
86 * returned for unknown **bpf_prog_type** values.
87 */
88LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
89
90enum libbpf_print_level {
91 LIBBPF_WARN,
92 LIBBPF_INFO,
93 LIBBPF_DEBUG,
94};
95
96typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
97 const char *, va_list ap);
98
99/**
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.
104 *
105 * This function is thread-safe.
106 */
107LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
108
109/* Hide internal to user */
110struct bpf_object;
111
112struct bpf_object_open_opts {
113 /* size of this struct, for forward/backward compatibility */
114 size_t sz;
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;
120 */
121 const char *object_name;
122 /* parse map definitions non-strictly, allowing extra attributes/data */
123 bool relaxed_maps;
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".
127 */
128 const char *pin_root_path;
129
130 __u32 :32; /* stub out now removed attach_prog_fd */
131
132 /* Additional kernel config content that augments and overrides
133 * system Kconfig for CONFIG_xxx externs.
134 */
135 const char *kconfig;
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.
141 */
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.
150 *
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.
157 *
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.
163 */
164 char *kernel_log_buf;
165 size_t kernel_log_size;
166 /*
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.
178 */
179 __u32 kernel_log_level;
180 /* Path to BPF FS mount point to derive BPF token from.
181 *
182 * Created BPF token will be used for all bpf() syscall operations
183 * that accept BPF token (e.g., map creation, BTF and program loads,
184 * etc) automatically within instantiated BPF object.
185 *
186 * If bpf_token_path is not specified, libbpf will consult
187 * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be
188 * taken as a value of bpf_token_path option and will force libbpf to
189 * either create BPF token from provided custom BPF FS path, or will
190 * disable implicit BPF token creation, if envvar value is an empty
191 * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are
192 * set at the same time.
193 *
194 * Setting bpf_token_path option to empty string disables libbpf's
195 * automatic attempt to create BPF token from default BPF FS mount
196 * point (/sys/fs/bpf), in case this default behavior is undesirable.
197 */
198 const char *bpf_token_path;
199
200 size_t :0;
201};
202#define bpf_object_open_opts__last_field bpf_token_path
203
204/**
205 * @brief **bpf_object__open()** creates a bpf_object by opening
206 * the BPF ELF object file pointed to by the passed path and loading it
207 * into memory.
208 * @param path BPF object file path.
209 * @return pointer to the new bpf_object; or NULL is returned on error,
210 * error code is stored in errno
211 */
212LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
213
214/**
215 * @brief **bpf_object__open_file()** creates a bpf_object by opening
216 * the BPF ELF object file pointed to by the passed path and loading it
217 * into memory.
218 * @param path BPF object file path
219 * @param opts options for how to load the bpf object, this parameter is
220 * optional and can be set to NULL
221 * @return pointer to the new bpf_object; or NULL is returned on error,
222 * error code is stored in errno
223 */
224LIBBPF_API struct bpf_object *
225bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
226
227/**
228 * @brief **bpf_object__open_mem()** creates a bpf_object by reading
229 * the BPF objects raw bytes from a memory buffer containing a valid
230 * BPF ELF object file.
231 * @param obj_buf pointer to the buffer containing ELF file bytes
232 * @param obj_buf_sz number of bytes in the buffer
233 * @param opts options for how to load the bpf object
234 * @return pointer to the new bpf_object; or NULL is returned on error,
235 * error code is stored in errno
236 */
237LIBBPF_API struct bpf_object *
238bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
239 const struct bpf_object_open_opts *opts);
240
241/**
242 * @brief **bpf_object__load()** loads BPF object into kernel.
243 * @param obj Pointer to a valid BPF object instance returned by
244 * **bpf_object__open*()** APIs
245 * @return 0, on success; negative error code, otherwise, error code is
246 * stored in errno
247 */
248LIBBPF_API int bpf_object__load(struct bpf_object *obj);
249
250/**
251 * @brief **bpf_object__close()** closes a BPF object and releases all
252 * resources.
253 * @param obj Pointer to a valid BPF object
254 */
255LIBBPF_API void bpf_object__close(struct bpf_object *obj);
256
257/**
258 * @brief **bpf_object__pin_maps()** pins each map contained within
259 * the BPF object at the passed directory.
260 * @param obj Pointer to a valid BPF object
261 * @param path A directory where maps should be pinned.
262 * @return 0, on success; negative error code, otherwise
263 *
264 * If `path` is NULL `bpf_map__pin` (which is being used on each map)
265 * will use the pin_path attribute of each map. In this case, maps that
266 * don't have a pin_path set will be ignored.
267 */
268LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
269
270/**
271 * @brief **bpf_object__unpin_maps()** unpins each map contained within
272 * the BPF object found in the passed directory.
273 * @param obj Pointer to a valid BPF object
274 * @param path A directory where pinned maps should be searched for.
275 * @return 0, on success; negative error code, otherwise
276 *
277 * If `path` is NULL `bpf_map__unpin` (which is being used on each map)
278 * will use the pin_path attribute of each map. In this case, maps that
279 * don't have a pin_path set will be ignored.
280 */
281LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
282 const char *path);
283LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
284 const char *path);
285LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
286 const char *path);
287LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
288LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path);
289
290LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
291LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
292LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
293
294struct btf;
295LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
296LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
297
298LIBBPF_API struct bpf_program *
299bpf_object__find_program_by_name(const struct bpf_object *obj,
300 const char *name);
301
302LIBBPF_API int
303libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
304 enum bpf_attach_type *expected_attach_type);
305LIBBPF_API int libbpf_attach_type_by_name(const char *name,
306 enum bpf_attach_type *attach_type);
307LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
308 enum bpf_attach_type attach_type);
309
310/* Accessors of bpf_program */
311struct bpf_program;
312
313LIBBPF_API struct bpf_program *
314bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
315
316#define bpf_object__for_each_program(pos, obj) \
317 for ((pos) = bpf_object__next_program((obj), NULL); \
318 (pos) != NULL; \
319 (pos) = bpf_object__next_program((obj), (pos)))
320
321LIBBPF_API struct bpf_program *
322bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
323
324LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
325 __u32 ifindex);
326
327LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
328LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
329LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
330LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
331LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
332LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
333
334struct bpf_insn;
335
336/**
337 * @brief **bpf_program__insns()** gives read-only access to BPF program's
338 * underlying BPF instructions.
339 * @param prog BPF program for which to return instructions
340 * @return a pointer to an array of BPF instructions that belong to the
341 * specified BPF program
342 *
343 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
344 * pointed to can be fetched using **bpf_program__insn_cnt()** API.
345 *
346 * Keep in mind, libbpf can modify and append/delete BPF program's
347 * instructions as it processes BPF object file and prepares everything for
348 * uploading into the kernel. So depending on the point in BPF object
349 * lifetime, **bpf_program__insns()** can return different sets of
350 * instructions. As an example, during BPF object load phase BPF program
351 * instructions will be CO-RE-relocated, BPF subprograms instructions will be
352 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
353 * returned before **bpf_object__load()** and after it might be quite
354 * different.
355 */
356LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
357
358/**
359 * @brief **bpf_program__set_insns()** can set BPF program's underlying
360 * BPF instructions.
361 *
362 * WARNING: This is a very advanced libbpf API and users need to know
363 * what they are doing. This should be used from prog_prepare_load_fn
364 * callback only.
365 *
366 * @param prog BPF program for which to return instructions
367 * @param new_insns a pointer to an array of BPF instructions
368 * @param new_insn_cnt number of `struct bpf_insn`'s that form
369 * specified BPF program
370 * @return 0, on success; negative error code, otherwise
371 */
372LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
373 struct bpf_insn *new_insns, size_t new_insn_cnt);
374
375/**
376 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
377 * that form specified BPF program.
378 * @param prog BPF program for which to return number of BPF instructions
379 *
380 * See **bpf_program__insns()** documentation for notes on how libbpf can
381 * change instructions and their count during different phases of
382 * **bpf_object** lifetime.
383 */
384LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
385
386LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
387
388/**
389 * @brief **bpf_program__pin()** pins the BPF program to a file
390 * in the BPF FS specified by a path. This increments the programs
391 * reference count, allowing it to stay loaded after the process
392 * which loaded it has exited.
393 *
394 * @param prog BPF program to pin, must already be loaded
395 * @param path file path in a BPF file system
396 * @return 0, on success; negative error code, otherwise
397 */
398LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
399
400/**
401 * @brief **bpf_program__unpin()** unpins the BPF program from a file
402 * in the BPFFS specified by a path. This decrements the programs
403 * reference count.
404 *
405 * The file pinning the BPF program can also be unlinked by a different
406 * process in which case this function will return an error.
407 *
408 * @param prog BPF program to unpin
409 * @param path file path to the pin in a BPF file system
410 * @return 0, on success; negative error code, otherwise
411 */
412LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
413LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
414
415struct bpf_link;
416
417LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
418LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
419LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
420/**
421 * @brief **bpf_link__pin()** pins the BPF link to a file
422 * in the BPF FS specified by a path. This increments the links
423 * reference count, allowing it to stay loaded after the process
424 * which loaded it has exited.
425 *
426 * @param link BPF link to pin, must already be loaded
427 * @param path file path in a BPF file system
428 * @return 0, on success; negative error code, otherwise
429 */
430
431LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
432
433/**
434 * @brief **bpf_link__unpin()** unpins the BPF link from a file
435 * in the BPFFS specified by a path. This decrements the links
436 * reference count.
437 *
438 * The file pinning the BPF link can also be unlinked by a different
439 * process in which case this function will return an error.
440 *
441 * @param prog BPF program to unpin
442 * @param path file path to the pin in a BPF file system
443 * @return 0, on success; negative error code, otherwise
444 */
445LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
446LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
447 struct bpf_program *prog);
448LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
449LIBBPF_API int bpf_link__detach(struct bpf_link *link);
450LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
451
452/**
453 * @brief **bpf_program__attach()** is a generic function for attaching
454 * a BPF program based on auto-detection of program type, attach type,
455 * and extra paremeters, where applicable.
456 *
457 * @param prog BPF program to attach
458 * @return Reference to the newly created BPF link; or NULL is returned on error,
459 * error code is stored in errno
460 *
461 * This is supported for:
462 * - kprobe/kretprobe (depends on SEC() definition)
463 * - uprobe/uretprobe (depends on SEC() definition)
464 * - tracepoint
465 * - raw tracepoint
466 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
467 */
468LIBBPF_API struct bpf_link *
469bpf_program__attach(const struct bpf_program *prog);
470
471struct bpf_perf_event_opts {
472 /* size of this struct, for forward/backward compatibility */
473 size_t sz;
474 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
475 __u64 bpf_cookie;
476 /* don't use BPF link when attach BPF program */
477 bool force_ioctl_attach;
478 size_t :0;
479};
480#define bpf_perf_event_opts__last_field force_ioctl_attach
481
482LIBBPF_API struct bpf_link *
483bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
484
485LIBBPF_API struct bpf_link *
486bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
487 const struct bpf_perf_event_opts *opts);
488
489/**
490 * enum probe_attach_mode - the mode to attach kprobe/uprobe
491 *
492 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will
493 * be returned if it is not supported by the kernel.
494 */
495enum probe_attach_mode {
496 /* attach probe in latest supported mode by kernel */
497 PROBE_ATTACH_MODE_DEFAULT = 0,
498 /* attach probe in legacy mode, using debugfs/tracefs */
499 PROBE_ATTACH_MODE_LEGACY,
500 /* create perf event with perf_event_open() syscall */
501 PROBE_ATTACH_MODE_PERF,
502 /* attach probe with BPF link */
503 PROBE_ATTACH_MODE_LINK,
504};
505
506struct bpf_kprobe_opts {
507 /* size of this struct, for forward/backward compatibility */
508 size_t sz;
509 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
510 __u64 bpf_cookie;
511 /* function's offset to install kprobe to */
512 size_t offset;
513 /* kprobe is return probe */
514 bool retprobe;
515 /* kprobe attach mode */
516 enum probe_attach_mode attach_mode;
517 size_t :0;
518};
519#define bpf_kprobe_opts__last_field attach_mode
520
521LIBBPF_API struct bpf_link *
522bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
523 const char *func_name);
524LIBBPF_API struct bpf_link *
525bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
526 const char *func_name,
527 const struct bpf_kprobe_opts *opts);
528
529struct bpf_kprobe_multi_opts {
530 /* size of this struct, for forward/backward compatibility */
531 size_t sz;
532 /* array of function symbols to attach */
533 const char **syms;
534 /* array of function addresses to attach */
535 const unsigned long *addrs;
536 /* array of user-provided values fetchable through bpf_get_attach_cookie */
537 const __u64 *cookies;
538 /* number of elements in syms/addrs/cookies arrays */
539 size_t cnt;
540 /* create return kprobes */
541 bool retprobe;
542 size_t :0;
543};
544
545#define bpf_kprobe_multi_opts__last_field retprobe
546
547LIBBPF_API struct bpf_link *
548bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
549 const char *pattern,
550 const struct bpf_kprobe_multi_opts *opts);
551
552struct bpf_uprobe_multi_opts {
553 /* size of this struct, for forward/backward compatibility */
554 size_t sz;
555 /* array of function symbols to attach to */
556 const char **syms;
557 /* array of function addresses to attach to */
558 const unsigned long *offsets;
559 /* optional, array of associated ref counter offsets */
560 const unsigned long *ref_ctr_offsets;
561 /* optional, array of associated BPF cookies */
562 const __u64 *cookies;
563 /* number of elements in syms/addrs/cookies arrays */
564 size_t cnt;
565 /* create return uprobes */
566 bool retprobe;
567 size_t :0;
568};
569
570#define bpf_uprobe_multi_opts__last_field retprobe
571
572/**
573 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
574 * to multiple uprobes with uprobe_multi link.
575 *
576 * User can specify 2 mutually exclusive set of inputs:
577 *
578 * 1) use only path/func_pattern/pid arguments
579 *
580 * 2) use path/pid with allowed combinations of
581 * syms/offsets/ref_ctr_offsets/cookies/cnt
582 *
583 * - syms and offsets are mutually exclusive
584 * - ref_ctr_offsets and cookies are optional
585 *
586 *
587 * @param prog BPF program to attach
588 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
589 * -1 for all processes
590 * @param binary_path Path to binary
591 * @param func_pattern Regular expression to specify functions to attach
592 * BPF program to
593 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
594 * @return 0, on success; negative error code, otherwise
595 */
596LIBBPF_API struct bpf_link *
597bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
598 pid_t pid,
599 const char *binary_path,
600 const char *func_pattern,
601 const struct bpf_uprobe_multi_opts *opts);
602
603struct bpf_ksyscall_opts {
604 /* size of this struct, for forward/backward compatibility */
605 size_t sz;
606 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
607 __u64 bpf_cookie;
608 /* attach as return probe? */
609 bool retprobe;
610 size_t :0;
611};
612#define bpf_ksyscall_opts__last_field retprobe
613
614/**
615 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
616 * to kernel syscall handler of a specified syscall. Optionally it's possible
617 * to request to install retprobe that will be triggered at syscall exit. It's
618 * also possible to associate BPF cookie (though options).
619 *
620 * Libbpf automatically will determine correct full kernel function name,
621 * which depending on system architecture and kernel version/configuration
622 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
623 * attach specified program using kprobe/kretprobe mechanism.
624 *
625 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
626 * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
627 *
628 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
629 * not handle all the calling convention quirks for mmap(), clone() and compat
630 * syscalls. It also only attaches to "native" syscall interfaces. If host
631 * system supports compat syscalls or defines 32-bit syscalls in 64-bit
632 * kernel, such syscall interfaces won't be attached to by libbpf.
633 *
634 * These limitations may or may not change in the future. Therefore it is
635 * recommended to use SEC("kprobe") for these syscalls or if working with
636 * compat and 32-bit interfaces is required.
637 *
638 * @param prog BPF program to attach
639 * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
640 * @param opts Additional options (see **struct bpf_ksyscall_opts**)
641 * @return Reference to the newly created BPF link; or NULL is returned on
642 * error, error code is stored in errno
643 */
644LIBBPF_API struct bpf_link *
645bpf_program__attach_ksyscall(const struct bpf_program *prog,
646 const char *syscall_name,
647 const struct bpf_ksyscall_opts *opts);
648
649struct bpf_uprobe_opts {
650 /* size of this struct, for forward/backward compatibility */
651 size_t sz;
652 /* offset of kernel reference counted USDT semaphore, added in
653 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
654 */
655 size_t ref_ctr_offset;
656 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
657 __u64 bpf_cookie;
658 /* uprobe is return probe, invoked at function return time */
659 bool retprobe;
660 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified
661 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while
662 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an
663 * offset within a function, specify func_name and use func_offset argument to specify
664 * offset within the function. Shared library functions must specify the shared library
665 * binary_path.
666 */
667 const char *func_name;
668 /* uprobe attach mode */
669 enum probe_attach_mode attach_mode;
670 size_t :0;
671};
672#define bpf_uprobe_opts__last_field attach_mode
673
674/**
675 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
676 * to the userspace function which is found by binary path and
677 * offset. You can optionally specify a particular proccess to attach
678 * to. You can also optionally attach the program to the function
679 * exit instead of entry.
680 *
681 * @param prog BPF program to attach
682 * @param retprobe Attach to function exit
683 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
684 * -1 for all processes
685 * @param binary_path Path to binary that contains the function symbol
686 * @param func_offset Offset within the binary of the function symbol
687 * @return Reference to the newly created BPF link; or NULL is returned on error,
688 * error code is stored in errno
689 */
690LIBBPF_API struct bpf_link *
691bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
692 pid_t pid, const char *binary_path,
693 size_t func_offset);
694
695/**
696 * @brief **bpf_program__attach_uprobe_opts()** is just like
697 * bpf_program__attach_uprobe() except with a options struct
698 * for various configurations.
699 *
700 * @param prog BPF program to attach
701 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
702 * -1 for all processes
703 * @param binary_path Path to binary that contains the function symbol
704 * @param func_offset Offset within the binary of the function symbol
705 * @param opts Options for altering program attachment
706 * @return Reference to the newly created BPF link; or NULL is returned on error,
707 * error code is stored in errno
708 */
709LIBBPF_API struct bpf_link *
710bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
711 const char *binary_path, size_t func_offset,
712 const struct bpf_uprobe_opts *opts);
713
714struct bpf_usdt_opts {
715 /* size of this struct, for forward/backward compatibility */
716 size_t sz;
717 /* custom user-provided value accessible through usdt_cookie() */
718 __u64 usdt_cookie;
719 size_t :0;
720};
721#define bpf_usdt_opts__last_field usdt_cookie
722
723/**
724 * @brief **bpf_program__attach_usdt()** is just like
725 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
726 * Statically Defined Tracepoint) attachment, instead of attaching to
727 * user-space function entry or exit.
728 *
729 * @param prog BPF program to attach
730 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
731 * -1 for all processes
732 * @param binary_path Path to binary that contains provided USDT probe
733 * @param usdt_provider USDT provider name
734 * @param usdt_name USDT probe name
735 * @param opts Options for altering program attachment
736 * @return Reference to the newly created BPF link; or NULL is returned on error,
737 * error code is stored in errno
738 */
739LIBBPF_API struct bpf_link *
740bpf_program__attach_usdt(const struct bpf_program *prog,
741 pid_t pid, const char *binary_path,
742 const char *usdt_provider, const char *usdt_name,
743 const struct bpf_usdt_opts *opts);
744
745struct bpf_tracepoint_opts {
746 /* size of this struct, for forward/backward compatibility */
747 size_t sz;
748 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
749 __u64 bpf_cookie;
750};
751#define bpf_tracepoint_opts__last_field bpf_cookie
752
753LIBBPF_API struct bpf_link *
754bpf_program__attach_tracepoint(const struct bpf_program *prog,
755 const char *tp_category,
756 const char *tp_name);
757LIBBPF_API struct bpf_link *
758bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
759 const char *tp_category,
760 const char *tp_name,
761 const struct bpf_tracepoint_opts *opts);
762
763LIBBPF_API struct bpf_link *
764bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
765 const char *tp_name);
766
767struct bpf_trace_opts {
768 /* size of this struct, for forward/backward compatibility */
769 size_t sz;
770 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
771 __u64 cookie;
772};
773#define bpf_trace_opts__last_field cookie
774
775LIBBPF_API struct bpf_link *
776bpf_program__attach_trace(const struct bpf_program *prog);
777LIBBPF_API struct bpf_link *
778bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
779
780LIBBPF_API struct bpf_link *
781bpf_program__attach_lsm(const struct bpf_program *prog);
782LIBBPF_API struct bpf_link *
783bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
784LIBBPF_API struct bpf_link *
785bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
786LIBBPF_API struct bpf_link *
787bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
788LIBBPF_API struct bpf_link *
789bpf_program__attach_freplace(const struct bpf_program *prog,
790 int target_fd, const char *attach_func_name);
791
792struct bpf_netfilter_opts {
793 /* size of this struct, for forward/backward compatibility */
794 size_t sz;
795
796 __u32 pf;
797 __u32 hooknum;
798 __s32 priority;
799 __u32 flags;
800};
801#define bpf_netfilter_opts__last_field flags
802
803LIBBPF_API struct bpf_link *
804bpf_program__attach_netfilter(const struct bpf_program *prog,
805 const struct bpf_netfilter_opts *opts);
806
807struct bpf_tcx_opts {
808 /* size of this struct, for forward/backward compatibility */
809 size_t sz;
810 __u32 flags;
811 __u32 relative_fd;
812 __u32 relative_id;
813 __u64 expected_revision;
814 size_t :0;
815};
816#define bpf_tcx_opts__last_field expected_revision
817
818LIBBPF_API struct bpf_link *
819bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
820 const struct bpf_tcx_opts *opts);
821
822struct bpf_netkit_opts {
823 /* size of this struct, for forward/backward compatibility */
824 size_t sz;
825 __u32 flags;
826 __u32 relative_fd;
827 __u32 relative_id;
828 __u64 expected_revision;
829 size_t :0;
830};
831#define bpf_netkit_opts__last_field expected_revision
832
833LIBBPF_API struct bpf_link *
834bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
835 const struct bpf_netkit_opts *opts);
836
837struct bpf_map;
838
839LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
840LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
841
842struct bpf_iter_attach_opts {
843 size_t sz; /* size of this struct for forward/backward compatibility */
844 union bpf_iter_link_info *link_info;
845 __u32 link_info_len;
846};
847#define bpf_iter_attach_opts__last_field link_info_len
848
849LIBBPF_API struct bpf_link *
850bpf_program__attach_iter(const struct bpf_program *prog,
851 const struct bpf_iter_attach_opts *opts);
852
853LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
854
855/**
856 * @brief **bpf_program__set_type()** sets the program
857 * type of the passed BPF program.
858 * @param prog BPF program to set the program type for
859 * @param type program type to set the BPF map to have
860 * @return error code; or 0 if no error. An error occurs
861 * if the object is already loaded.
862 *
863 * This must be called before the BPF object is loaded,
864 * otherwise it has no effect and an error is returned.
865 */
866LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
867 enum bpf_prog_type type);
868
869LIBBPF_API enum bpf_attach_type
870bpf_program__expected_attach_type(const struct bpf_program *prog);
871
872/**
873 * @brief **bpf_program__set_expected_attach_type()** sets the
874 * attach type of the passed BPF program. This is used for
875 * auto-detection of attachment when programs are loaded.
876 * @param prog BPF program to set the attach type for
877 * @param type attach type to set the BPF map to have
878 * @return error code; or 0 if no error. An error occurs
879 * if the object is already loaded.
880 *
881 * This must be called before the BPF object is loaded,
882 * otherwise it has no effect and an error is returned.
883 */
884LIBBPF_API int
885bpf_program__set_expected_attach_type(struct bpf_program *prog,
886 enum bpf_attach_type type);
887
888LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
889LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
890
891/* Per-program log level and log buffer getters/setters.
892 * See bpf_object_open_opts comments regarding log_level and log_buf
893 * interactions.
894 */
895LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
896LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
897LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
898LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
899
900/**
901 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
902 * for supported BPF program types:
903 * - BTF-aware raw tracepoints (tp_btf);
904 * - fentry/fexit/fmod_ret;
905 * - lsm;
906 * - freplace.
907 * @param prog BPF program to set the attach type for
908 * @param type attach type to set the BPF map to have
909 * @return error code; or 0 if no error occurred.
910 */
911LIBBPF_API int
912bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
913 const char *attach_func_name);
914
915/**
916 * @brief **bpf_object__find_map_by_name()** returns BPF map of
917 * the given name, if it exists within the passed BPF object
918 * @param obj BPF object
919 * @param name name of the BPF map
920 * @return BPF map instance, if such map exists within the BPF object;
921 * or NULL otherwise.
922 */
923LIBBPF_API struct bpf_map *
924bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
925
926LIBBPF_API int
927bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
928
929LIBBPF_API struct bpf_map *
930bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
931
932#define bpf_object__for_each_map(pos, obj) \
933 for ((pos) = bpf_object__next_map((obj), NULL); \
934 (pos) != NULL; \
935 (pos) = bpf_object__next_map((obj), (pos)))
936#define bpf_map__for_each bpf_object__for_each_map
937
938LIBBPF_API struct bpf_map *
939bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
940
941/**
942 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
943 * BPF map during BPF object load phase.
944 * @param map the BPF map instance
945 * @param autocreate whether to create BPF map during BPF object load
946 * @return 0 on success; -EBUSY if BPF object was already loaded
947 *
948 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
949 * BPF map. By default, libbpf will attempt to create every single BPF map
950 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
951 * and fill in map FD in BPF instructions.
952 *
953 * This API allows to opt-out of this process for specific map instance. This
954 * can be useful if host kernel doesn't support such BPF map type or used
955 * combination of flags and user application wants to avoid creating such
956 * a map in the first place. User is still responsible to make sure that their
957 * BPF-side code that expects to use such missing BPF map is recognized by BPF
958 * verifier as dead code, otherwise BPF verifier will reject such BPF program.
959 */
960LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
961LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
962
963/**
964 * @brief **bpf_map__fd()** gets the file descriptor of the passed
965 * BPF map
966 * @param map the BPF map instance
967 * @return the file descriptor; or -EINVAL in case of an error
968 */
969LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
970LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
971/* get map name */
972LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
973/* get/set map type */
974LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
975LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
976/* get/set map size (max_entries) */
977LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
978LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
979/* get/set map flags */
980LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
981LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
982/* get/set map NUMA node */
983LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
984LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
985/* get/set map key size */
986LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
987LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
988/* get map value size */
989LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
990/**
991 * @brief **bpf_map__set_value_size()** sets map value size.
992 * @param map the BPF map instance
993 * @return 0, on success; negative error, otherwise
994 *
995 * There is a special case for maps with associated memory-mapped regions, like
996 * the global data section maps (bss, data, rodata). When this function is used
997 * on such a map, the mapped region is resized. Afterward, an attempt is made to
998 * adjust the corresponding BTF info. This attempt is best-effort and can only
999 * succeed if the last variable of the data section map is an array. The array
1000 * BTF type is replaced by a new BTF array type with a different length.
1001 * Any previously existing pointers returned from bpf_map__initial_value() or
1002 * corresponding data section skeleton pointer must be reinitialized.
1003 */
1004LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
1005/* get map key/value BTF type IDs */
1006LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
1007LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
1008/* get/set map if_index */
1009LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
1010LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
1011/* get/set map map_extra flags */
1012LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
1013LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
1014
1015LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
1016 const void *data, size_t size);
1017LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize);
1018
1019/**
1020 * @brief **bpf_map__is_internal()** tells the caller whether or not the
1021 * passed map is a special map created by libbpf automatically for things like
1022 * global variables, __ksym externs, Kconfig values, etc
1023 * @param map the bpf_map
1024 * @return true, if the map is an internal map; false, otherwise
1025 */
1026LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
1027
1028/**
1029 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
1030 * BPF map should be pinned. This does not actually create the 'pin'.
1031 * @param map The bpf_map
1032 * @param path The path
1033 * @return 0, on success; negative error, otherwise
1034 */
1035LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
1036
1037/**
1038 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
1039 * BPF map should be pinned.
1040 * @param map The bpf_map
1041 * @return The path string; which can be NULL
1042 */
1043LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
1044
1045/**
1046 * @brief **bpf_map__is_pinned()** tells the caller whether or not the
1047 * passed map has been pinned via a 'pin' file.
1048 * @param map The bpf_map
1049 * @return true, if the map is pinned; false, otherwise
1050 */
1051LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
1052
1053/**
1054 * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
1055 * for the BPF map. This increments the reference count on the
1056 * BPF map which will keep the BPF map loaded even after the
1057 * userspace process which loaded it has exited.
1058 * @param map The bpf_map to pin
1059 * @param path A file path for the 'pin'
1060 * @return 0, on success; negative error, otherwise
1061 *
1062 * If `path` is NULL the maps `pin_path` attribute will be used. If this is
1063 * also NULL, an error will be returned and the map will not be pinned.
1064 */
1065LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
1066
1067/**
1068 * @brief **bpf_map__unpin()** removes the file that serves as a
1069 * 'pin' for the BPF map.
1070 * @param map The bpf_map to unpin
1071 * @param path A file path for the 'pin'
1072 * @return 0, on success; negative error, otherwise
1073 *
1074 * The `path` parameter can be NULL, in which case the `pin_path`
1075 * map attribute is unpinned. If both the `path` parameter and
1076 * `pin_path` map attribute are set, they must be equal.
1077 */
1078LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
1079
1080LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
1081LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
1082
1083/**
1084 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
1085 * corresponding to provided key.
1086 * @param map BPF map to lookup element in
1087 * @param key pointer to memory containing bytes of the key used for lookup
1088 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1089 * @param value pointer to memory in which looked up value will be stored
1090 * @param value_sz size in byte of value data memory; it has to match BPF map
1091 * definition's **value_size**. For per-CPU BPF maps value size has to be
1092 * a product of BPF map value size and number of possible CPUs in the system
1093 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1094 * per-CPU values value size has to be aligned up to closest 8 bytes for
1095 * alignment reasons, so expected size is: `round_up(value_size, 8)
1096 * * libbpf_num_possible_cpus()`.
1097 * @flags extra flags passed to kernel for this operation
1098 * @return 0, on success; negative error, otherwise
1099 *
1100 * **bpf_map__lookup_elem()** is high-level equivalent of
1101 * **bpf_map_lookup_elem()** API with added check for key and value size.
1102 */
1103LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1104 const void *key, size_t key_sz,
1105 void *value, size_t value_sz, __u64 flags);
1106
1107/**
1108 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1109 * map that corresponds to provided key.
1110 * @param map BPF map to insert to or update element in
1111 * @param key pointer to memory containing bytes of the key
1112 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1113 * @param value pointer to memory containing bytes of the value
1114 * @param value_sz size in byte of value data memory; it has to match BPF map
1115 * definition's **value_size**. For per-CPU BPF maps value size has to be
1116 * a product of BPF map value size and number of possible CPUs in the system
1117 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1118 * per-CPU values value size has to be aligned up to closest 8 bytes for
1119 * alignment reasons, so expected size is: `round_up(value_size, 8)
1120 * * libbpf_num_possible_cpus()`.
1121 * @flags extra flags passed to kernel for this operation
1122 * @return 0, on success; negative error, otherwise
1123 *
1124 * **bpf_map__update_elem()** is high-level equivalent of
1125 * **bpf_map_update_elem()** API with added check for key and value size.
1126 */
1127LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1128 const void *key, size_t key_sz,
1129 const void *value, size_t value_sz, __u64 flags);
1130
1131/**
1132 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1133 * corresponds to provided key.
1134 * @param map BPF map to delete element from
1135 * @param key pointer to memory containing bytes of the key
1136 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1137 * @flags extra flags passed to kernel for this operation
1138 * @return 0, on success; negative error, otherwise
1139 *
1140 * **bpf_map__delete_elem()** is high-level equivalent of
1141 * **bpf_map_delete_elem()** API with added check for key size.
1142 */
1143LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1144 const void *key, size_t key_sz, __u64 flags);
1145
1146/**
1147 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1148 * corresponding to provided key and atomically delete it afterwards.
1149 * @param map BPF map to lookup element in
1150 * @param key pointer to memory containing bytes of the key used for lookup
1151 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1152 * @param value pointer to memory in which looked up value will be stored
1153 * @param value_sz size in byte of value data memory; it has to match BPF map
1154 * definition's **value_size**. For per-CPU BPF maps value size has to be
1155 * a product of BPF map value size and number of possible CPUs in the system
1156 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1157 * per-CPU values value size has to be aligned up to closest 8 bytes for
1158 * alignment reasons, so expected size is: `round_up(value_size, 8)
1159 * * libbpf_num_possible_cpus()`.
1160 * @flags extra flags passed to kernel for this operation
1161 * @return 0, on success; negative error, otherwise
1162 *
1163 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1164 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1165 */
1166LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1167 const void *key, size_t key_sz,
1168 void *value, size_t value_sz, __u64 flags);
1169
1170/**
1171 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1172 * fetching next key that follows current key.
1173 * @param map BPF map to fetch next key from
1174 * @param cur_key pointer to memory containing bytes of current key or NULL to
1175 * fetch the first key
1176 * @param next_key pointer to memory to write next key into
1177 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1178 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1179 * negative error, otherwise
1180 *
1181 * **bpf_map__get_next_key()** is high-level equivalent of
1182 * **bpf_map_get_next_key()** API with added check for key size.
1183 */
1184LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1185 const void *cur_key, void *next_key, size_t key_sz);
1186
1187struct bpf_xdp_set_link_opts {
1188 size_t sz;
1189 int old_fd;
1190 size_t :0;
1191};
1192#define bpf_xdp_set_link_opts__last_field old_fd
1193
1194struct bpf_xdp_attach_opts {
1195 size_t sz;
1196 int old_prog_fd;
1197 size_t :0;
1198};
1199#define bpf_xdp_attach_opts__last_field old_prog_fd
1200
1201struct bpf_xdp_query_opts {
1202 size_t sz;
1203 __u32 prog_id; /* output */
1204 __u32 drv_prog_id; /* output */
1205 __u32 hw_prog_id; /* output */
1206 __u32 skb_prog_id; /* output */
1207 __u8 attach_mode; /* output */
1208 __u64 feature_flags; /* output */
1209 __u32 xdp_zc_max_segs; /* output */
1210 size_t :0;
1211};
1212#define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1213
1214LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1215 const struct bpf_xdp_attach_opts *opts);
1216LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1217 const struct bpf_xdp_attach_opts *opts);
1218LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1219LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1220
1221/* TC related API */
1222enum bpf_tc_attach_point {
1223 BPF_TC_INGRESS = 1 << 0,
1224 BPF_TC_EGRESS = 1 << 1,
1225 BPF_TC_CUSTOM = 1 << 2,
1226};
1227
1228#define BPF_TC_PARENT(a, b) \
1229 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1230
1231enum bpf_tc_flags {
1232 BPF_TC_F_REPLACE = 1 << 0,
1233};
1234
1235struct bpf_tc_hook {
1236 size_t sz;
1237 int ifindex;
1238 enum bpf_tc_attach_point attach_point;
1239 __u32 parent;
1240 size_t :0;
1241};
1242#define bpf_tc_hook__last_field parent
1243
1244struct bpf_tc_opts {
1245 size_t sz;
1246 int prog_fd;
1247 __u32 flags;
1248 __u32 prog_id;
1249 __u32 handle;
1250 __u32 priority;
1251 size_t :0;
1252};
1253#define bpf_tc_opts__last_field priority
1254
1255LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1256LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1257LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1258 struct bpf_tc_opts *opts);
1259LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1260 const struct bpf_tc_opts *opts);
1261LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1262 struct bpf_tc_opts *opts);
1263
1264/* Ring buffer APIs */
1265struct ring_buffer;
1266struct ring;
1267struct user_ring_buffer;
1268
1269typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1270
1271struct ring_buffer_opts {
1272 size_t sz; /* size of this struct, for forward/backward compatibility */
1273};
1274
1275#define ring_buffer_opts__last_field sz
1276
1277LIBBPF_API struct ring_buffer *
1278ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1279 const struct ring_buffer_opts *opts);
1280LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1281LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1282 ring_buffer_sample_fn sample_cb, void *ctx);
1283LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1284LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1285LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1286
1287/**
1288 * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given
1289 * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance.
1290 *
1291 * @param rb A ringbuffer manager object.
1292 * @param idx An index into the ringbuffers contained within the ringbuffer
1293 * manager object. The index is 0-based and corresponds to the order in which
1294 * ring_buffer__add was called.
1295 * @return A ringbuffer object on success; NULL and errno set if the index is
1296 * invalid.
1297 */
1298LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb,
1299 unsigned int idx);
1300
1301/**
1302 * @brief **ring__consumer_pos()** returns the current consumer position in the
1303 * given ringbuffer.
1304 *
1305 * @param r A ringbuffer object.
1306 * @return The current consumer position.
1307 */
1308LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r);
1309
1310/**
1311 * @brief **ring__producer_pos()** returns the current producer position in the
1312 * given ringbuffer.
1313 *
1314 * @param r A ringbuffer object.
1315 * @return The current producer position.
1316 */
1317LIBBPF_API unsigned long ring__producer_pos(const struct ring *r);
1318
1319/**
1320 * @brief **ring__avail_data_size()** returns the number of bytes in the
1321 * ringbuffer not yet consumed. This has no locking associated with it, so it
1322 * can be inaccurate if operations are ongoing while this is called. However, it
1323 * should still show the correct trend over the long-term.
1324 *
1325 * @param r A ringbuffer object.
1326 * @return The number of bytes not yet consumed.
1327 */
1328LIBBPF_API size_t ring__avail_data_size(const struct ring *r);
1329
1330/**
1331 * @brief **ring__size()** returns the total size of the ringbuffer's map data
1332 * area (excluding special producer/consumer pages). Effectively this gives the
1333 * amount of usable bytes of data inside the ringbuffer.
1334 *
1335 * @param r A ringbuffer object.
1336 * @return The total size of the ringbuffer map data area.
1337 */
1338LIBBPF_API size_t ring__size(const struct ring *r);
1339
1340/**
1341 * @brief **ring__map_fd()** returns the file descriptor underlying the given
1342 * ringbuffer.
1343 *
1344 * @param r A ringbuffer object.
1345 * @return The underlying ringbuffer file descriptor
1346 */
1347LIBBPF_API int ring__map_fd(const struct ring *r);
1348
1349/**
1350 * @brief **ring__consume()** consumes available ringbuffer data without event
1351 * polling.
1352 *
1353 * @param r A ringbuffer object.
1354 * @return The number of records consumed (or INT_MAX, whichever is less), or
1355 * a negative number if any of the callbacks return an error.
1356 */
1357LIBBPF_API int ring__consume(struct ring *r);
1358
1359struct user_ring_buffer_opts {
1360 size_t sz; /* size of this struct, for forward/backward compatibility */
1361};
1362
1363#define user_ring_buffer_opts__last_field sz
1364
1365/**
1366 * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1367 * buffer.
1368 *
1369 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1370 * @param opts Options for how the ring buffer should be created.
1371 * @return A user ring buffer on success; NULL and errno being set on a
1372 * failure.
1373 */
1374LIBBPF_API struct user_ring_buffer *
1375user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1376
1377/**
1378 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1379 * user ring buffer.
1380 * @param rb A pointer to a user ring buffer.
1381 * @param size The size of the sample, in bytes.
1382 * @return A pointer to an 8-byte aligned reserved region of the user ring
1383 * buffer; NULL, and errno being set if a sample could not be reserved.
1384 *
1385 * This function is *not* thread safe, and callers must synchronize accessing
1386 * this function if there are multiple producers. If a size is requested that
1387 * is larger than the size of the entire ring buffer, errno will be set to
1388 * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1389 * but currently does not have enough space, errno is set to ENOSPC and NULL is
1390 * returned.
1391 *
1392 * After initializing the sample, callers must invoke
1393 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1394 * the sample must be freed with **user_ring_buffer__discard()**.
1395 */
1396LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1397
1398/**
1399 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1400 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1401 * available.
1402 * @param rb The user ring buffer.
1403 * @param size The size of the sample, in bytes.
1404 * @param timeout_ms The amount of time, in milliseconds, for which the caller
1405 * should block when waiting for a sample. -1 causes the caller to block
1406 * indefinitely.
1407 * @return A pointer to an 8-byte aligned reserved region of the user ring
1408 * buffer; NULL, and errno being set if a sample could not be reserved.
1409 *
1410 * This function is *not* thread safe, and callers must synchronize
1411 * accessing this function if there are multiple producers
1412 *
1413 * If **timeout_ms** is -1, the function will block indefinitely until a sample
1414 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1415 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1416 * will occur and the function will return immediately after attempting to
1417 * reserve a sample.
1418 *
1419 * If **size** is larger than the size of the entire ring buffer, errno is set
1420 * to E2BIG and NULL is returned. If the ring buffer could accommodate
1421 * **size**, but currently does not have enough space, the caller will block
1422 * until at most **timeout_ms** has elapsed. If insufficient space is available
1423 * at that time, errno is set to ENOSPC, and NULL is returned.
1424 *
1425 * The kernel guarantees that it will wake up this thread to check if
1426 * sufficient space is available in the ring buffer at least once per
1427 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1428 * least one sample is consumed, and the BPF program did not invoke the
1429 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1430 * kernel does not guarantee this. If the helper function is invoked with
1431 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1432 * consumed.
1433 *
1434 * When a sample of size **size** is found within **timeout_ms**, a pointer to
1435 * the sample is returned. After initializing the sample, callers must invoke
1436 * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1437 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1438 */
1439LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1440 __u32 size,
1441 int timeout_ms);
1442
1443/**
1444 * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1445 * into the ring buffer.
1446 * @param rb The user ring buffer.
1447 * @param sample A reserved sample.
1448 *
1449 * It is not necessary to synchronize amongst multiple producers when invoking
1450 * this function.
1451 */
1452LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1453
1454/**
1455 * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1456 * @param rb The user ring buffer.
1457 * @param sample A reserved sample.
1458 *
1459 * It is not necessary to synchronize amongst multiple producers when invoking
1460 * this function.
1461 */
1462LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1463
1464/**
1465 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1466 * created with **user_ring_buffer__new()**.
1467 * @param rb The user ring buffer being freed.
1468 */
1469LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1470
1471/* Perf buffer APIs */
1472struct perf_buffer;
1473
1474typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1475 void *data, __u32 size);
1476typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1477
1478/* common use perf buffer options */
1479struct perf_buffer_opts {
1480 size_t sz;
1481 __u32 sample_period;
1482 size_t :0;
1483};
1484#define perf_buffer_opts__last_field sample_period
1485
1486/**
1487 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1488 * BPF_PERF_EVENT_ARRAY map
1489 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1490 * code to send data over to user-space
1491 * @param page_cnt number of memory pages allocated for each per-CPU buffer
1492 * @param sample_cb function called on each received data record
1493 * @param lost_cb function called when record loss has occurred
1494 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1495 * @return a new instance of struct perf_buffer on success, NULL on error with
1496 * *errno* containing an error code
1497 */
1498LIBBPF_API struct perf_buffer *
1499perf_buffer__new(int map_fd, size_t page_cnt,
1500 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1501 const struct perf_buffer_opts *opts);
1502
1503enum bpf_perf_event_ret {
1504 LIBBPF_PERF_EVENT_DONE = 0,
1505 LIBBPF_PERF_EVENT_ERROR = -1,
1506 LIBBPF_PERF_EVENT_CONT = -2,
1507};
1508
1509struct perf_event_header;
1510
1511typedef enum bpf_perf_event_ret
1512(*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1513
1514/* raw perf buffer options, giving most power and control */
1515struct perf_buffer_raw_opts {
1516 size_t sz;
1517 long :0;
1518 long :0;
1519 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1520 * max_entries of given PERF_EVENT_ARRAY map)
1521 */
1522 int cpu_cnt;
1523 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1524 int *cpus;
1525 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1526 int *map_keys;
1527};
1528#define perf_buffer_raw_opts__last_field map_keys
1529
1530struct perf_event_attr;
1531
1532LIBBPF_API struct perf_buffer *
1533perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1534 perf_buffer_event_fn event_cb, void *ctx,
1535 const struct perf_buffer_raw_opts *opts);
1536
1537LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1538LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1539LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1540LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1541LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1542LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1543LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1544/**
1545 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1546 * memory region of the ring buffer.
1547 * This ring buffer can be used to implement a custom events consumer.
1548 * The ring buffer starts with the *struct perf_event_mmap_page*, which
1549 * holds the ring buffer managment fields, when accessing the header
1550 * structure it's important to be SMP aware.
1551 * You can refer to *perf_event_read_simple* for a simple example.
1552 * @param pb the perf buffer structure
1553 * @param buf_idx the buffer index to retreive
1554 * @param buf (out) gets the base pointer of the mmap()'ed memory
1555 * @param buf_size (out) gets the size of the mmap()'ed region
1556 * @return 0 on success, negative error code for failure
1557 */
1558LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1559 size_t *buf_size);
1560
1561struct bpf_prog_linfo;
1562struct bpf_prog_info;
1563
1564LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1565LIBBPF_API struct bpf_prog_linfo *
1566bpf_prog_linfo__new(const struct bpf_prog_info *info);
1567LIBBPF_API const struct bpf_line_info *
1568bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1569 __u64 addr, __u32 func_idx, __u32 nr_skip);
1570LIBBPF_API const struct bpf_line_info *
1571bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1572 __u32 insn_off, __u32 nr_skip);
1573
1574/*
1575 * Probe for supported system features
1576 *
1577 * Note that running many of these probes in a short amount of time can cause
1578 * the kernel to reach the maximal size of lockable memory allowed for the
1579 * user, causing subsequent probes to fail. In this case, the caller may want
1580 * to adjust that limit with setrlimit().
1581 */
1582
1583/**
1584 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1585 * BPF programs of a given type.
1586 * @param prog_type BPF program type to detect kernel support for
1587 * @param opts reserved for future extensibility, should be NULL
1588 * @return 1, if given program type is supported; 0, if given program type is
1589 * not supported; negative error code if feature detection failed or can't be
1590 * performed
1591 *
1592 * Make sure the process has required set of CAP_* permissions (or runs as
1593 * root) when performing feature checking.
1594 */
1595LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1596/**
1597 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1598 * BPF maps of a given type.
1599 * @param map_type BPF map type to detect kernel support for
1600 * @param opts reserved for future extensibility, should be NULL
1601 * @return 1, if given map type is supported; 0, if given map type is
1602 * not supported; negative error code if feature detection failed or can't be
1603 * performed
1604 *
1605 * Make sure the process has required set of CAP_* permissions (or runs as
1606 * root) when performing feature checking.
1607 */
1608LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1609/**
1610 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1611 * use of a given BPF helper from specified BPF program type.
1612 * @param prog_type BPF program type used to check the support of BPF helper
1613 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1614 * @param opts reserved for future extensibility, should be NULL
1615 * @return 1, if given combination of program type and helper is supported; 0,
1616 * if the combination is not supported; negative error code if feature
1617 * detection for provided input arguments failed or can't be performed
1618 *
1619 * Make sure the process has required set of CAP_* permissions (or runs as
1620 * root) when performing feature checking.
1621 */
1622LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1623 enum bpf_func_id helper_id, const void *opts);
1624
1625/**
1626 * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1627 * number of possible CPUs that the host kernel supports and expects.
1628 * @return number of possible CPUs; or error code on failure
1629 *
1630 * Example usage:
1631 *
1632 * int ncpus = libbpf_num_possible_cpus();
1633 * if (ncpus < 0) {
1634 * // error handling
1635 * }
1636 * long values[ncpus];
1637 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1638 */
1639LIBBPF_API int libbpf_num_possible_cpus(void);
1640
1641struct bpf_map_skeleton {
1642 const char *name;
1643 struct bpf_map **map;
1644 void **mmaped;
1645};
1646
1647struct bpf_prog_skeleton {
1648 const char *name;
1649 struct bpf_program **prog;
1650 struct bpf_link **link;
1651};
1652
1653struct bpf_object_skeleton {
1654 size_t sz; /* size of this struct, for forward/backward compatibility */
1655
1656 const char *name;
1657 const void *data;
1658 size_t data_sz;
1659
1660 struct bpf_object **obj;
1661
1662 int map_cnt;
1663 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1664 struct bpf_map_skeleton *maps;
1665
1666 int prog_cnt;
1667 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1668 struct bpf_prog_skeleton *progs;
1669};
1670
1671LIBBPF_API int
1672bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1673 const struct bpf_object_open_opts *opts);
1674LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1675LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1676LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1677LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1678
1679struct bpf_var_skeleton {
1680 const char *name;
1681 struct bpf_map **map;
1682 void **addr;
1683};
1684
1685struct bpf_object_subskeleton {
1686 size_t sz; /* size of this struct, for forward/backward compatibility */
1687
1688 const struct bpf_object *obj;
1689
1690 int map_cnt;
1691 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1692 struct bpf_map_skeleton *maps;
1693
1694 int prog_cnt;
1695 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1696 struct bpf_prog_skeleton *progs;
1697
1698 int var_cnt;
1699 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1700 struct bpf_var_skeleton *vars;
1701};
1702
1703LIBBPF_API int
1704bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1705LIBBPF_API void
1706bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1707
1708struct gen_loader_opts {
1709 size_t sz; /* size of this struct, for forward/backward compatibility */
1710 const char *data;
1711 const char *insns;
1712 __u32 data_sz;
1713 __u32 insns_sz;
1714};
1715
1716#define gen_loader_opts__last_field insns_sz
1717LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1718 struct gen_loader_opts *opts);
1719
1720enum libbpf_tristate {
1721 TRI_NO = 0,
1722 TRI_YES = 1,
1723 TRI_MODULE = 2,
1724};
1725
1726struct bpf_linker_opts {
1727 /* size of this struct, for forward/backward compatibility */
1728 size_t sz;
1729};
1730#define bpf_linker_opts__last_field sz
1731
1732struct bpf_linker_file_opts {
1733 /* size of this struct, for forward/backward compatibility */
1734 size_t sz;
1735};
1736#define bpf_linker_file_opts__last_field sz
1737
1738struct bpf_linker;
1739
1740LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1741LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1742 const char *filename,
1743 const struct bpf_linker_file_opts *opts);
1744LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1745LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1746
1747/*
1748 * Custom handling of BPF program's SEC() definitions
1749 */
1750
1751struct bpf_prog_load_opts; /* defined in bpf.h */
1752
1753/* Called during bpf_object__open() for each recognized BPF program. Callback
1754 * can use various bpf_program__set_*() setters to adjust whatever properties
1755 * are necessary.
1756 */
1757typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1758
1759/* Called right before libbpf performs bpf_prog_load() to load BPF program
1760 * into the kernel. Callback can adjust opts as necessary.
1761 */
1762typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1763 struct bpf_prog_load_opts *opts, long cookie);
1764
1765/* Called during skeleton attach or through bpf_program__attach(). If
1766 * auto-attach is not supported, callback should return 0 and set link to
1767 * NULL (it's not considered an error during skeleton attach, but it will be
1768 * an error for bpf_program__attach() calls). On error, error should be
1769 * returned directly and link set to NULL. On success, return 0 and set link
1770 * to a valid struct bpf_link.
1771 */
1772typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1773 struct bpf_link **link);
1774
1775struct libbpf_prog_handler_opts {
1776 /* size of this struct, for forward/backward compatibility */
1777 size_t sz;
1778 /* User-provided value that is passed to prog_setup_fn,
1779 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1780 * register one set of callbacks for multiple SEC() definitions and
1781 * still be able to distinguish them, if necessary. For example,
1782 * libbpf itself is using this to pass necessary flags (e.g.,
1783 * sleepable flag) to a common internal SEC() handler.
1784 */
1785 long cookie;
1786 /* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1787 * Callback is optional, pass NULL if it's not necessary.
1788 */
1789 libbpf_prog_setup_fn_t prog_setup_fn;
1790 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1791 * Callback is optional, pass NULL if it's not necessary.
1792 */
1793 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1794 /* BPF program attach callback (see libbpf_prog_attach_fn_t).
1795 * Callback is optional, pass NULL if it's not necessary.
1796 */
1797 libbpf_prog_attach_fn_t prog_attach_fn;
1798};
1799#define libbpf_prog_handler_opts__last_field prog_attach_fn
1800
1801/**
1802 * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1803 * SEC() handler.
1804 * @param sec section prefix for which custom handler is registered
1805 * @param prog_type BPF program type associated with specified section
1806 * @param exp_attach_type Expected BPF attach type associated with specified section
1807 * @param opts optional cookie, callbacks, and other extra options
1808 * @return Non-negative handler ID is returned on success. This handler ID has
1809 * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1810 * custom handler. Negative error code is returned on error.
1811 *
1812 * *sec* defines which SEC() definitions are handled by this custom handler
1813 * registration. *sec* can have few different forms:
1814 * - if *sec* is just a plain string (e.g., "abc"), it will match only
1815 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1816 * in an error;
1817 * - if *sec* is of the form "abc/", proper SEC() form is
1818 * SEC("abc/something"), where acceptable "something" should be checked by
1819 * *prog_init_fn* callback, if there are additional restrictions;
1820 * - if *sec* is of the form "abc+", it will successfully match both
1821 * SEC("abc") and SEC("abc/whatever") forms;
1822 * - if *sec* is NULL, custom handler is registered for any BPF program that
1823 * doesn't match any of the registered (custom or libbpf's own) SEC()
1824 * handlers. There could be only one such generic custom handler registered
1825 * at any given time.
1826 *
1827 * All custom handlers (except the one with *sec* == NULL) are processed
1828 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1829 * SEC() handlers by registering custom ones for the same section prefix
1830 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1831 * handler).
1832 *
1833 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1834 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1835 * to ensure synchronization if there is a risk of running this API from
1836 * multiple threads simultaneously.
1837 */
1838LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1839 enum bpf_prog_type prog_type,
1840 enum bpf_attach_type exp_attach_type,
1841 const struct libbpf_prog_handler_opts *opts);
1842/**
1843 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1844 * custom BPF program SEC() handler.
1845 * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1846 * after successful registration
1847 * @return 0 on success, negative error code if handler isn't found
1848 *
1849 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1850 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1851 * to ensure synchronization if there is a risk of running this API from
1852 * multiple threads simultaneously.
1853 */
1854LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1855
1856#ifdef __cplusplus
1857} /* extern "C" */
1858#endif
1859
1860#endif /* __LIBBPF_LIBBPF_H */
1/*
2 * Common eBPF ELF object loading operations.
3 *
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 */
8#ifndef __BPF_LIBBPF_H
9#define __BPF_LIBBPF_H
10
11#include <stdio.h>
12#include <stdbool.h>
13#include <linux/err.h>
14
15enum libbpf_errno {
16 __LIBBPF_ERRNO__START = 4000,
17
18 /* Something wrong in libelf */
19 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
20 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
21 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
22 LIBBPF_ERRNO__ENDIAN, /* Endian missmatch */
23 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
24 LIBBPF_ERRNO__RELOC, /* Relocation failed */
25 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
26 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
27 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
28 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
29 __LIBBPF_ERRNO__END,
30};
31
32int libbpf_strerror(int err, char *buf, size_t size);
33
34/*
35 * In include/linux/compiler-gcc.h, __printf is defined. However
36 * it should be better if libbpf.h doesn't depend on Linux header file.
37 * So instead of __printf, here we use gcc attribute directly.
38 */
39typedef int (*libbpf_print_fn_t)(const char *, ...)
40 __attribute__((format(printf, 1, 2)));
41
42void libbpf_set_print(libbpf_print_fn_t warn,
43 libbpf_print_fn_t info,
44 libbpf_print_fn_t debug);
45
46/* Hide internal to user */
47struct bpf_object;
48
49struct bpf_object *bpf_object__open(const char *path);
50struct bpf_object *bpf_object__open_buffer(void *obj_buf,
51 size_t obj_buf_sz,
52 const char *name);
53void bpf_object__close(struct bpf_object *object);
54
55/* Load/unload object into/from kernel */
56int bpf_object__load(struct bpf_object *obj);
57int bpf_object__unload(struct bpf_object *obj);
58const char *bpf_object__get_name(struct bpf_object *obj);
59unsigned int bpf_object__get_kversion(struct bpf_object *obj);
60
61struct bpf_object *bpf_object__next(struct bpf_object *prev);
62#define bpf_object__for_each_safe(pos, tmp) \
63 for ((pos) = bpf_object__next(NULL), \
64 (tmp) = bpf_object__next(pos); \
65 (pos) != NULL; \
66 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
67
68/* Accessors of bpf_program. */
69struct bpf_program;
70struct bpf_program *bpf_program__next(struct bpf_program *prog,
71 struct bpf_object *obj);
72
73#define bpf_object__for_each_program(pos, obj) \
74 for ((pos) = bpf_program__next(NULL, (obj)); \
75 (pos) != NULL; \
76 (pos) = bpf_program__next((pos), (obj)))
77
78typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
79 void *);
80
81int bpf_program__set_private(struct bpf_program *prog, void *priv,
82 bpf_program_clear_priv_t clear_priv);
83
84int bpf_program__get_private(struct bpf_program *prog,
85 void **ppriv);
86
87const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
88
89int bpf_program__fd(struct bpf_program *prog);
90
91struct bpf_insn;
92
93/*
94 * Libbpf allows callers to adjust BPF programs before being loaded
95 * into kernel. One program in an object file can be transform into
96 * multiple variants to be attached to different code.
97 *
98 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
99 * are APIs for this propose.
100 *
101 * - bpf_program_prep_t:
102 * It defines 'preprocessor', which is a caller defined function
103 * passed to libbpf through bpf_program__set_prep(), and will be
104 * called before program is loaded. The processor should adjust
105 * the program one time for each instances according to the number
106 * passed to it.
107 *
108 * - bpf_program__set_prep:
109 * Attachs a preprocessor to a BPF program. The number of instances
110 * whould be created is also passed through this function.
111 *
112 * - bpf_program__nth_fd:
113 * After the program is loaded, get resuling fds from bpf program for
114 * each instances.
115 *
116 * If bpf_program__set_prep() is not used, the program whould be loaded
117 * without adjustment during bpf_object__load(). The program has only
118 * one instance. In this case bpf_program__fd(prog) is equal to
119 * bpf_program__nth_fd(prog, 0).
120 */
121
122struct bpf_prog_prep_result {
123 /*
124 * If not NULL, load new instruction array.
125 * If set to NULL, don't load this instance.
126 */
127 struct bpf_insn *new_insn_ptr;
128 int new_insn_cnt;
129
130 /* If not NULL, result fd is set to it */
131 int *pfd;
132};
133
134/*
135 * Parameters of bpf_program_prep_t:
136 * - prog: The bpf_program being loaded.
137 * - n: Index of instance being generated.
138 * - insns: BPF instructions array.
139 * - insns_cnt:Number of instructions in insns.
140 * - res: Output parameter, result of transformation.
141 *
142 * Return value:
143 * - Zero: pre-processing success.
144 * - Non-zero: pre-processing, stop loading.
145 */
146typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
147 struct bpf_insn *insns, int insns_cnt,
148 struct bpf_prog_prep_result *res);
149
150int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
151 bpf_program_prep_t prep);
152
153int bpf_program__nth_fd(struct bpf_program *prog, int n);
154
155/*
156 * We don't need __attribute__((packed)) now since it is
157 * unnecessary for 'bpf_map_def' because they are all aligned.
158 * In addition, using it will trigger -Wpacked warning message,
159 * and will be treated as an error due to -Werror.
160 */
161struct bpf_map_def {
162 unsigned int type;
163 unsigned int key_size;
164 unsigned int value_size;
165 unsigned int max_entries;
166};
167
168/*
169 * There is another 'struct bpf_map' in include/linux/map.h. However,
170 * it is not a uapi header so no need to consider name clash.
171 */
172struct bpf_map;
173struct bpf_map *
174bpf_object__get_map_by_name(struct bpf_object *obj, const char *name);
175
176struct bpf_map *
177bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
178#define bpf_map__for_each(pos, obj) \
179 for ((pos) = bpf_map__next(NULL, (obj)); \
180 (pos) != NULL; \
181 (pos) = bpf_map__next((pos), (obj)))
182
183int bpf_map__get_fd(struct bpf_map *map);
184int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef);
185const char *bpf_map__get_name(struct bpf_map *map);
186
187typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
188int bpf_map__set_private(struct bpf_map *map, void *priv,
189 bpf_map_clear_priv_t clear_priv);
190int bpf_map__get_private(struct bpf_map *map, void **ppriv);
191
192#endif