xref: /linux/tools/lib/bpf/libbpf.h (revision d0d106a2bd21499901299160744e5fe9f4c83ddb)
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
24 extern "C" {
25 #endif
26 
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);
30 
31 enum 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 
52 LIBBPF_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  */
61 LIBBPF_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  */
70 LIBBPF_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  */
79 LIBBPF_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  */
88 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
89 
90 enum libbpf_print_level {
91         LIBBPF_WARN,
92         LIBBPF_INFO,
93         LIBBPF_DEBUG,
94 };
95 
96 typedef 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. If the user callback
102  * is not set, messages are logged to stderr by default. The verbosity of these
103  * messages can be controlled by setting the environment variable
104  * LIBBPF_LOG_LEVEL to either warn, info, or debug.
105  * @param fn The log print function. If NULL, libbpf won't print anything.
106  * @return Pointer to old print function.
107  *
108  * This function is thread-safe.
109  */
110 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
111 
112 /* Hide internal to user */
113 struct bpf_object;
114 
115 struct bpf_object_open_opts {
116 	/* size of this struct, for forward/backward compatibility */
117 	size_t sz;
118 	/* object name override, if provided:
119 	 * - for object open from file, this will override setting object
120 	 *   name from file path's base name;
121 	 * - for object open from memory buffer, this will specify an object
122 	 *   name and will override default "<addr>-<buf-size>" name;
123 	 */
124 	const char *object_name;
125 	/* parse map definitions non-strictly, allowing extra attributes/data */
126 	bool relaxed_maps;
127 	/* maps that set the 'pinning' attribute in their definition will have
128 	 * their pin_path attribute set to a file in this directory, and be
129 	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
130 	 */
131 	const char *pin_root_path;
132 
133 	__u32 :32; /* stub out now removed attach_prog_fd */
134 
135 	/* Additional kernel config content that augments and overrides
136 	 * system Kconfig for CONFIG_xxx externs.
137 	 */
138 	const char *kconfig;
139 	/* Path to the custom BTF to be used for BPF CO-RE relocations.
140 	 * This custom BTF completely replaces the use of vmlinux BTF
141 	 * for the purpose of CO-RE relocations.
142 	 * NOTE: any other BPF feature (e.g., fentry/fexit programs,
143 	 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
144 	 */
145 	const char *btf_custom_path;
146 	/* Pointer to a buffer for storing kernel logs for applicable BPF
147 	 * commands. Valid kernel_log_size has to be specified as well and are
148 	 * passed-through to bpf() syscall. Keep in mind that kernel might
149 	 * fail operation with -ENOSPC error if provided buffer is too small
150 	 * to contain entire log output.
151 	 * See the comment below for kernel_log_level for interaction between
152 	 * log_buf and log_level settings.
153 	 *
154 	 * If specified, this log buffer will be passed for:
155 	 *   - each BPF progral load (BPF_PROG_LOAD) attempt, unless overridden
156 	 *     with bpf_program__set_log() on per-program level, to get
157 	 *     BPF verifier log output.
158 	 *   - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get
159 	 *     BTF sanity checking log.
160 	 *
161 	 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite
162 	 * previous contents, so if you need more fine-grained control, set
163 	 * per-program buffer with bpf_program__set_log_buf() to preserve each
164 	 * individual program's verification log. Keep using kernel_log_buf
165 	 * for BTF verification log, if necessary.
166 	 */
167 	char *kernel_log_buf;
168 	size_t kernel_log_size;
169 	/*
170 	 * Log level can be set independently from log buffer. Log_level=0
171 	 * means that libbpf will attempt loading BTF or program without any
172 	 * logging requested, but will retry with either its own or custom log
173 	 * buffer, if provided, and log_level=1 on any error.
174 	 * And vice versa, setting log_level>0 will request BTF or prog
175 	 * loading with verbose log from the first attempt (and as such also
176 	 * for successfully loaded BTF or program), and the actual log buffer
177 	 * could be either libbpf's own auto-allocated log buffer, if
178 	 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf.
179 	 * If user didn't provide custom log buffer, libbpf will emit captured
180 	 * logs through its print callback.
181 	 */
182 	__u32 kernel_log_level;
183 	/* Path to BPF FS mount point to derive BPF token from.
184 	 *
185 	 * Created BPF token will be used for all bpf() syscall operations
186 	 * that accept BPF token (e.g., map creation, BTF and program loads,
187 	 * etc) automatically within instantiated BPF object.
188 	 *
189 	 * If bpf_token_path is not specified, libbpf will consult
190 	 * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be
191 	 * taken as a value of bpf_token_path option and will force libbpf to
192 	 * either create BPF token from provided custom BPF FS path, or will
193 	 * disable implicit BPF token creation, if envvar value is an empty
194 	 * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are
195 	 * set at the same time.
196 	 *
197 	 * Setting bpf_token_path option to empty string disables libbpf's
198 	 * automatic attempt to create BPF token from default BPF FS mount
199 	 * point (/sys/fs/bpf), in case this default behavior is undesirable.
200 	 */
201 	const char *bpf_token_path;
202 
203 	size_t :0;
204 };
205 #define bpf_object_open_opts__last_field bpf_token_path
206 
207 /**
208  * @brief **bpf_object__open()** creates a bpf_object by opening
209  * the BPF ELF object file pointed to by the passed path and loading it
210  * into memory.
211  * @param path BPF object file path.
212  * @return pointer to the new bpf_object; or NULL is returned on error,
213  * error code is stored in errno
214  */
215 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
216 
217 /**
218  * @brief **bpf_object__open_file()** creates a bpf_object by opening
219  * the BPF ELF object file pointed to by the passed path and loading it
220  * into memory.
221  * @param path BPF object file path
222  * @param opts options for how to load the bpf object, this parameter is
223  * optional and can be set to NULL
224  * @return pointer to the new bpf_object; or NULL is returned on error,
225  * error code is stored in errno
226  */
227 LIBBPF_API struct bpf_object *
228 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
229 
230 /**
231  * @brief **bpf_object__open_mem()** creates a bpf_object by reading
232  * the BPF objects raw bytes from a memory buffer containing a valid
233  * BPF ELF object file.
234  * @param obj_buf pointer to the buffer containing ELF file bytes
235  * @param obj_buf_sz number of bytes in the buffer
236  * @param opts options for how to load the bpf object
237  * @return pointer to the new bpf_object; or NULL is returned on error,
238  * error code is stored in errno
239  */
240 LIBBPF_API struct bpf_object *
241 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
242 		     const struct bpf_object_open_opts *opts);
243 
244 /**
245  * @brief **bpf_object__load()** loads BPF object into kernel.
246  * @param obj Pointer to a valid BPF object instance returned by
247  * **bpf_object__open*()** APIs
248  * @return 0, on success; negative error code, otherwise, error code is
249  * stored in errno
250  */
251 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
252 
253 /**
254  * @brief **bpf_object__close()** closes a BPF object and releases all
255  * resources.
256  * @param obj Pointer to a valid BPF object
257  */
258 LIBBPF_API void bpf_object__close(struct bpf_object *obj);
259 
260 /**
261  * @brief **bpf_object__pin_maps()** pins each map contained within
262  * the BPF object at the passed directory.
263  * @param obj Pointer to a valid BPF object
264  * @param path A directory where maps should be pinned.
265  * @return 0, on success; negative error code, otherwise
266  *
267  * If `path` is NULL `bpf_map__pin` (which is being used on each map)
268  * will use the pin_path attribute of each map. In this case, maps that
269  * don't have a pin_path set will be ignored.
270  */
271 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
272 
273 /**
274  * @brief **bpf_object__unpin_maps()** unpins each map contained within
275  * the BPF object found in the passed directory.
276  * @param obj Pointer to a valid BPF object
277  * @param path A directory where pinned maps should be searched for.
278  * @return 0, on success; negative error code, otherwise
279  *
280  * If `path` is NULL `bpf_map__unpin` (which is being used on each map)
281  * will use the pin_path attribute of each map. In this case, maps that
282  * don't have a pin_path set will be ignored.
283  */
284 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
285 				      const char *path);
286 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
287 					const char *path);
288 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
289 					  const char *path);
290 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
291 LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path);
292 
293 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
294 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
295 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
296 
297 /**
298  * @brief **bpf_object__token_fd** is an accessor for BPF token FD associated
299  * with BPF object.
300  * @param obj Pointer to a valid BPF object
301  * @return BPF token FD or -1, if it wasn't set
302  */
303 LIBBPF_API int bpf_object__token_fd(const struct bpf_object *obj);
304 
305 struct btf;
306 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
307 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
308 
309 LIBBPF_API struct bpf_program *
310 bpf_object__find_program_by_name(const struct bpf_object *obj,
311 				 const char *name);
312 
313 LIBBPF_API int
314 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
315 			 enum bpf_attach_type *expected_attach_type);
316 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
317 					  enum bpf_attach_type *attach_type);
318 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
319 					  enum bpf_attach_type attach_type);
320 
321 /* Accessors of bpf_program */
322 struct bpf_program;
323 
324 LIBBPF_API struct bpf_program *
325 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
326 
327 #define bpf_object__for_each_program(pos, obj)			\
328 	for ((pos) = bpf_object__next_program((obj), NULL);	\
329 	     (pos) != NULL;					\
330 	     (pos) = bpf_object__next_program((obj), (pos)))
331 
332 LIBBPF_API struct bpf_program *
333 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
334 
335 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
336 					 __u32 ifindex);
337 
338 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
339 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
340 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
341 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
342 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
343 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
344 
345 struct bpf_insn;
346 
347 /**
348  * @brief **bpf_program__insns()** gives read-only access to BPF program's
349  * underlying BPF instructions.
350  * @param prog BPF program for which to return instructions
351  * @return a pointer to an array of BPF instructions that belong to the
352  * specified BPF program
353  *
354  * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
355  * pointed to can be fetched using **bpf_program__insn_cnt()** API.
356  *
357  * Keep in mind, libbpf can modify and append/delete BPF program's
358  * instructions as it processes BPF object file and prepares everything for
359  * uploading into the kernel. So depending on the point in BPF object
360  * lifetime, **bpf_program__insns()** can return different sets of
361  * instructions. As an example, during BPF object load phase BPF program
362  * instructions will be CO-RE-relocated, BPF subprograms instructions will be
363  * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
364  * returned before **bpf_object__load()** and after it might be quite
365  * different.
366  */
367 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
368 
369 /**
370  * @brief **bpf_program__set_insns()** can set BPF program's underlying
371  * BPF instructions.
372  *
373  * WARNING: This is a very advanced libbpf API and users need to know
374  * what they are doing. This should be used from prog_prepare_load_fn
375  * callback only.
376  *
377  * @param prog BPF program for which to return instructions
378  * @param new_insns a pointer to an array of BPF instructions
379  * @param new_insn_cnt number of `struct bpf_insn`'s that form
380  * specified BPF program
381  * @return 0, on success; negative error code, otherwise
382  */
383 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
384 				      struct bpf_insn *new_insns, size_t new_insn_cnt);
385 
386 /**
387  * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
388  * that form specified BPF program.
389  * @param prog BPF program for which to return number of BPF instructions
390  *
391  * See **bpf_program__insns()** documentation for notes on how libbpf can
392  * change instructions and their count during different phases of
393  * **bpf_object** lifetime.
394  */
395 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
396 
397 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
398 
399 /**
400  * @brief **bpf_program__pin()** pins the BPF program to a file
401  * in the BPF FS specified by a path. This increments the programs
402  * reference count, allowing it to stay loaded after the process
403  * which loaded it has exited.
404  *
405  * @param prog BPF program to pin, must already be loaded
406  * @param path file path in a BPF file system
407  * @return 0, on success; negative error code, otherwise
408  */
409 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
410 
411 /**
412  * @brief **bpf_program__unpin()** unpins the BPF program from a file
413  * in the BPFFS specified by a path. This decrements the programs
414  * reference count.
415  *
416  * The file pinning the BPF program can also be unlinked by a different
417  * process in which case this function will return an error.
418  *
419  * @param prog BPF program to unpin
420  * @param path file path to the pin in a BPF file system
421  * @return 0, on success; negative error code, otherwise
422  */
423 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
424 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
425 
426 struct bpf_link;
427 
428 LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
429 LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
430 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
431 /**
432  * @brief **bpf_link__pin()** pins the BPF link to a file
433  * in the BPF FS specified by a path. This increments the links
434  * reference count, allowing it to stay loaded after the process
435  * which loaded it has exited.
436  *
437  * @param link BPF link to pin, must already be loaded
438  * @param path file path in a BPF file system
439  * @return 0, on success; negative error code, otherwise
440  */
441 
442 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
443 
444 /**
445  * @brief **bpf_link__unpin()** unpins the BPF link from a file
446  * in the BPFFS specified by a path. This decrements the links
447  * reference count.
448  *
449  * The file pinning the BPF link can also be unlinked by a different
450  * process in which case this function will return an error.
451  *
452  * @param prog BPF program to unpin
453  * @param path file path to the pin in a BPF file system
454  * @return 0, on success; negative error code, otherwise
455  */
456 LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
457 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
458 					struct bpf_program *prog);
459 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
460 LIBBPF_API int bpf_link__detach(struct bpf_link *link);
461 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
462 
463 /**
464  * @brief **bpf_program__attach()** is a generic function for attaching
465  * a BPF program based on auto-detection of program type, attach type,
466  * and extra parameters, where applicable.
467  *
468  * @param prog BPF program to attach
469  * @return Reference to the newly created BPF link; or NULL is returned on error,
470  * error code is stored in errno
471  *
472  * This is supported for:
473  *   - kprobe/kretprobe (depends on SEC() definition)
474  *   - uprobe/uretprobe (depends on SEC() definition)
475  *   - tracepoint
476  *   - raw tracepoint
477  *   - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
478  */
479 LIBBPF_API struct bpf_link *
480 bpf_program__attach(const struct bpf_program *prog);
481 
482 struct bpf_perf_event_opts {
483 	/* size of this struct, for forward/backward compatibility */
484 	size_t sz;
485 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
486 	__u64 bpf_cookie;
487 	/* don't use BPF link when attach BPF program */
488 	bool force_ioctl_attach;
489 	size_t :0;
490 };
491 #define bpf_perf_event_opts__last_field force_ioctl_attach
492 
493 LIBBPF_API struct bpf_link *
494 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
495 
496 LIBBPF_API struct bpf_link *
497 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
498 				    const struct bpf_perf_event_opts *opts);
499 
500 /**
501  * enum probe_attach_mode - the mode to attach kprobe/uprobe
502  *
503  * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will
504  * be returned if it is not supported by the kernel.
505  */
506 enum probe_attach_mode {
507 	/* attach probe in latest supported mode by kernel */
508 	PROBE_ATTACH_MODE_DEFAULT = 0,
509 	/* attach probe in legacy mode, using debugfs/tracefs */
510 	PROBE_ATTACH_MODE_LEGACY,
511 	/* create perf event with perf_event_open() syscall */
512 	PROBE_ATTACH_MODE_PERF,
513 	/* attach probe with BPF link */
514 	PROBE_ATTACH_MODE_LINK,
515 };
516 
517 struct bpf_kprobe_opts {
518 	/* size of this struct, for forward/backward compatibility */
519 	size_t sz;
520 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
521 	__u64 bpf_cookie;
522 	/* function's offset to install kprobe to */
523 	size_t offset;
524 	/* kprobe is return probe */
525 	bool retprobe;
526 	/* kprobe attach mode */
527 	enum probe_attach_mode attach_mode;
528 	size_t :0;
529 };
530 #define bpf_kprobe_opts__last_field attach_mode
531 
532 LIBBPF_API struct bpf_link *
533 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
534 			   const char *func_name);
535 LIBBPF_API struct bpf_link *
536 bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
537                                 const char *func_name,
538                                 const struct bpf_kprobe_opts *opts);
539 
540 struct bpf_kprobe_multi_opts {
541 	/* size of this struct, for forward/backward compatibility */
542 	size_t sz;
543 	/* array of function symbols to attach */
544 	const char **syms;
545 	/* array of function addresses to attach */
546 	const unsigned long *addrs;
547 	/* array of user-provided values fetchable through bpf_get_attach_cookie */
548 	const __u64 *cookies;
549 	/* number of elements in syms/addrs/cookies arrays */
550 	size_t cnt;
551 	/* create return kprobes */
552 	bool retprobe;
553 	/* create session kprobes */
554 	bool session;
555 	/* enforce unique match */
556 	bool unique_match;
557 	size_t :0;
558 };
559 
560 #define bpf_kprobe_multi_opts__last_field unique_match
561 
562 LIBBPF_API struct bpf_link *
563 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
564 				      const char *pattern,
565 				      const struct bpf_kprobe_multi_opts *opts);
566 
567 struct bpf_uprobe_multi_opts {
568 	/* size of this struct, for forward/backward compatibility */
569 	size_t sz;
570 	/* array of function symbols to attach to */
571 	const char **syms;
572 	/* array of function addresses to attach to */
573 	const unsigned long *offsets;
574 	/* optional, array of associated ref counter offsets */
575 	const unsigned long *ref_ctr_offsets;
576 	/* optional, array of associated BPF cookies */
577 	const __u64 *cookies;
578 	/* number of elements in syms/addrs/cookies arrays */
579 	size_t cnt;
580 	/* create return uprobes */
581 	bool retprobe;
582 	/* create session kprobes */
583 	bool session;
584 	size_t :0;
585 };
586 
587 #define bpf_uprobe_multi_opts__last_field session
588 
589 /**
590  * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
591  * to multiple uprobes with uprobe_multi link.
592  *
593  * User can specify 2 mutually exclusive set of inputs:
594  *
595  *   1) use only path/func_pattern/pid arguments
596  *
597  *   2) use path/pid with allowed combinations of
598  *      syms/offsets/ref_ctr_offsets/cookies/cnt
599  *
600  *      - syms and offsets are mutually exclusive
601  *      - ref_ctr_offsets and cookies are optional
602  *
603  *
604  * @param prog BPF program to attach
605  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
606  * -1 for all processes
607  * @param binary_path Path to binary
608  * @param func_pattern Regular expression to specify functions to attach
609  * BPF program to
610  * @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
611  * @return 0, on success; negative error code, otherwise
612  */
613 LIBBPF_API struct bpf_link *
614 bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
615 				 pid_t pid,
616 				 const char *binary_path,
617 				 const char *func_pattern,
618 				 const struct bpf_uprobe_multi_opts *opts);
619 
620 struct bpf_ksyscall_opts {
621 	/* size of this struct, for forward/backward compatibility */
622 	size_t sz;
623 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
624 	__u64 bpf_cookie;
625 	/* attach as return probe? */
626 	bool retprobe;
627 	size_t :0;
628 };
629 #define bpf_ksyscall_opts__last_field retprobe
630 
631 /**
632  * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
633  * to kernel syscall handler of a specified syscall. Optionally it's possible
634  * to request to install retprobe that will be triggered at syscall exit. It's
635  * also possible to associate BPF cookie (though options).
636  *
637  * Libbpf automatically will determine correct full kernel function name,
638  * which depending on system architecture and kernel version/configuration
639  * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
640  * attach specified program using kprobe/kretprobe mechanism.
641  *
642  * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
643  * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
644  *
645  * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
646  * not handle all the calling convention quirks for mmap(), clone() and compat
647  * syscalls. It also only attaches to "native" syscall interfaces. If host
648  * system supports compat syscalls or defines 32-bit syscalls in 64-bit
649  * kernel, such syscall interfaces won't be attached to by libbpf.
650  *
651  * These limitations may or may not change in the future. Therefore it is
652  * recommended to use SEC("kprobe") for these syscalls or if working with
653  * compat and 32-bit interfaces is required.
654  *
655  * @param prog BPF program to attach
656  * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
657  * @param opts Additional options (see **struct bpf_ksyscall_opts**)
658  * @return Reference to the newly created BPF link; or NULL is returned on
659  * error, error code is stored in errno
660  */
661 LIBBPF_API struct bpf_link *
662 bpf_program__attach_ksyscall(const struct bpf_program *prog,
663 			     const char *syscall_name,
664 			     const struct bpf_ksyscall_opts *opts);
665 
666 struct bpf_uprobe_opts {
667 	/* size of this struct, for forward/backward compatibility */
668 	size_t sz;
669 	/* offset of kernel reference counted USDT semaphore, added in
670 	 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
671 	 */
672 	size_t ref_ctr_offset;
673 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
674 	__u64 bpf_cookie;
675 	/* uprobe is return probe, invoked at function return time */
676 	bool retprobe;
677 	/* Function name to attach to.  Could be an unqualified ("abc") or library-qualified
678 	 * "abc@LIBXYZ" name.  To specify function entry, func_name should be set while
679 	 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0.  To trace an
680 	 * offset within a function, specify func_name and use func_offset argument to specify
681 	 * offset within the function.  Shared library functions must specify the shared library
682 	 * binary_path.
683 	 */
684 	const char *func_name;
685 	/* uprobe attach mode */
686 	enum probe_attach_mode attach_mode;
687 	size_t :0;
688 };
689 #define bpf_uprobe_opts__last_field attach_mode
690 
691 /**
692  * @brief **bpf_program__attach_uprobe()** attaches a BPF program
693  * to the userspace function which is found by binary path and
694  * offset. You can optionally specify a particular process to attach
695  * to. You can also optionally attach the program to the function
696  * exit instead of entry.
697  *
698  * @param prog BPF program to attach
699  * @param retprobe Attach to function exit
700  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
701  * -1 for all processes
702  * @param binary_path Path to binary that contains the function symbol
703  * @param func_offset Offset within the binary of the function symbol
704  * @return Reference to the newly created BPF link; or NULL is returned on error,
705  * error code is stored in errno
706  */
707 LIBBPF_API struct bpf_link *
708 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
709 			   pid_t pid, const char *binary_path,
710 			   size_t func_offset);
711 
712 /**
713  * @brief **bpf_program__attach_uprobe_opts()** is just like
714  * bpf_program__attach_uprobe() except with a options struct
715  * for various configurations.
716  *
717  * @param prog BPF program to attach
718  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
719  * -1 for all processes
720  * @param binary_path Path to binary that contains the function symbol
721  * @param func_offset Offset within the binary of the function symbol
722  * @param opts Options for altering program attachment
723  * @return Reference to the newly created BPF link; or NULL is returned on error,
724  * error code is stored in errno
725  */
726 LIBBPF_API struct bpf_link *
727 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
728 				const char *binary_path, size_t func_offset,
729 				const struct bpf_uprobe_opts *opts);
730 
731 struct bpf_usdt_opts {
732 	/* size of this struct, for forward/backward compatibility */
733 	size_t sz;
734 	/* custom user-provided value accessible through usdt_cookie() */
735 	__u64 usdt_cookie;
736 	size_t :0;
737 };
738 #define bpf_usdt_opts__last_field usdt_cookie
739 
740 /**
741  * @brief **bpf_program__attach_usdt()** is just like
742  * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
743  * Statically Defined Tracepoint) attachment, instead of attaching to
744  * user-space function entry or exit.
745  *
746  * @param prog BPF program to attach
747  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
748  * -1 for all processes
749  * @param binary_path Path to binary that contains provided USDT probe
750  * @param usdt_provider USDT provider name
751  * @param usdt_name USDT probe name
752  * @param opts Options for altering program attachment
753  * @return Reference to the newly created BPF link; or NULL is returned on error,
754  * error code is stored in errno
755  */
756 LIBBPF_API struct bpf_link *
757 bpf_program__attach_usdt(const struct bpf_program *prog,
758 			 pid_t pid, const char *binary_path,
759 			 const char *usdt_provider, const char *usdt_name,
760 			 const struct bpf_usdt_opts *opts);
761 
762 struct bpf_tracepoint_opts {
763 	/* size of this struct, for forward/backward compatibility */
764 	size_t sz;
765 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
766 	__u64 bpf_cookie;
767 };
768 #define bpf_tracepoint_opts__last_field bpf_cookie
769 
770 LIBBPF_API struct bpf_link *
771 bpf_program__attach_tracepoint(const struct bpf_program *prog,
772 			       const char *tp_category,
773 			       const char *tp_name);
774 LIBBPF_API struct bpf_link *
775 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
776 				    const char *tp_category,
777 				    const char *tp_name,
778 				    const struct bpf_tracepoint_opts *opts);
779 
780 struct bpf_raw_tracepoint_opts {
781 	size_t sz; /* size of this struct for forward/backward compatibility */
782 	__u64 cookie;
783 	size_t :0;
784 };
785 #define bpf_raw_tracepoint_opts__last_field cookie
786 
787 LIBBPF_API struct bpf_link *
788 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
789 				   const char *tp_name);
790 LIBBPF_API struct bpf_link *
791 bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog,
792 					const char *tp_name,
793 					struct bpf_raw_tracepoint_opts *opts);
794 
795 struct bpf_trace_opts {
796 	/* size of this struct, for forward/backward compatibility */
797 	size_t sz;
798 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
799 	__u64 cookie;
800 };
801 #define bpf_trace_opts__last_field cookie
802 
803 LIBBPF_API struct bpf_link *
804 bpf_program__attach_trace(const struct bpf_program *prog);
805 LIBBPF_API struct bpf_link *
806 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
807 
808 LIBBPF_API struct bpf_link *
809 bpf_program__attach_lsm(const struct bpf_program *prog);
810 LIBBPF_API struct bpf_link *
811 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
812 LIBBPF_API struct bpf_link *
813 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
814 LIBBPF_API struct bpf_link *
815 bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd);
816 LIBBPF_API struct bpf_link *
817 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
818 LIBBPF_API struct bpf_link *
819 bpf_program__attach_freplace(const struct bpf_program *prog,
820 			     int target_fd, const char *attach_func_name);
821 
822 struct bpf_netfilter_opts {
823 	/* size of this struct, for forward/backward compatibility */
824 	size_t sz;
825 
826 	__u32 pf;
827 	__u32 hooknum;
828 	__s32 priority;
829 	__u32 flags;
830 };
831 #define bpf_netfilter_opts__last_field flags
832 
833 LIBBPF_API struct bpf_link *
834 bpf_program__attach_netfilter(const struct bpf_program *prog,
835 			      const struct bpf_netfilter_opts *opts);
836 
837 struct bpf_tcx_opts {
838 	/* size of this struct, for forward/backward compatibility */
839 	size_t sz;
840 	__u32 flags;
841 	__u32 relative_fd;
842 	__u32 relative_id;
843 	__u64 expected_revision;
844 	size_t :0;
845 };
846 #define bpf_tcx_opts__last_field expected_revision
847 
848 LIBBPF_API struct bpf_link *
849 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
850 			const struct bpf_tcx_opts *opts);
851 
852 struct bpf_netkit_opts {
853 	/* size of this struct, for forward/backward compatibility */
854 	size_t sz;
855 	__u32 flags;
856 	__u32 relative_fd;
857 	__u32 relative_id;
858 	__u64 expected_revision;
859 	size_t :0;
860 };
861 #define bpf_netkit_opts__last_field expected_revision
862 
863 LIBBPF_API struct bpf_link *
864 bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
865 			   const struct bpf_netkit_opts *opts);
866 
867 struct bpf_map;
868 
869 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
870 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
871 
872 struct bpf_iter_attach_opts {
873 	size_t sz; /* size of this struct for forward/backward compatibility */
874 	union bpf_iter_link_info *link_info;
875 	__u32 link_info_len;
876 };
877 #define bpf_iter_attach_opts__last_field link_info_len
878 
879 LIBBPF_API struct bpf_link *
880 bpf_program__attach_iter(const struct bpf_program *prog,
881 			 const struct bpf_iter_attach_opts *opts);
882 
883 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
884 
885 /**
886  * @brief **bpf_program__set_type()** sets the program
887  * type of the passed BPF program.
888  * @param prog BPF program to set the program type for
889  * @param type program type to set the BPF map to have
890  * @return error code; or 0 if no error. An error occurs
891  * if the object is already loaded.
892  *
893  * This must be called before the BPF object is loaded,
894  * otherwise it has no effect and an error is returned.
895  */
896 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
897 				     enum bpf_prog_type type);
898 
899 LIBBPF_API enum bpf_attach_type
900 bpf_program__expected_attach_type(const struct bpf_program *prog);
901 
902 /**
903  * @brief **bpf_program__set_expected_attach_type()** sets the
904  * attach type of the passed BPF program. This is used for
905  * auto-detection of attachment when programs are loaded.
906  * @param prog BPF program to set the attach type for
907  * @param type attach type to set the BPF map to have
908  * @return error code; or 0 if no error. An error occurs
909  * if the object is already loaded.
910  *
911  * This must be called before the BPF object is loaded,
912  * otherwise it has no effect and an error is returned.
913  */
914 LIBBPF_API int
915 bpf_program__set_expected_attach_type(struct bpf_program *prog,
916 				      enum bpf_attach_type type);
917 
918 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
919 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
920 
921 /* Per-program log level and log buffer getters/setters.
922  * See bpf_object_open_opts comments regarding log_level and log_buf
923  * interactions.
924  */
925 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
926 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
927 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
928 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
929 
930 /**
931  * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
932  * for supported BPF program types:
933  *   - BTF-aware raw tracepoints (tp_btf);
934  *   - fentry/fexit/fmod_ret;
935  *   - lsm;
936  *   - freplace.
937  * @param prog BPF program to set the attach type for
938  * @param type attach type to set the BPF map to have
939  * @return error code; or 0 if no error occurred.
940  */
941 LIBBPF_API int
942 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
943 			       const char *attach_func_name);
944 
945 /**
946  * @brief **bpf_object__find_map_by_name()** returns BPF map of
947  * the given name, if it exists within the passed BPF object
948  * @param obj BPF object
949  * @param name name of the BPF map
950  * @return BPF map instance, if such map exists within the BPF object;
951  * or NULL otherwise.
952  */
953 LIBBPF_API struct bpf_map *
954 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
955 
956 LIBBPF_API int
957 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
958 
959 LIBBPF_API struct bpf_map *
960 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
961 
962 #define bpf_object__for_each_map(pos, obj)		\
963 	for ((pos) = bpf_object__next_map((obj), NULL);	\
964 	     (pos) != NULL;				\
965 	     (pos) = bpf_object__next_map((obj), (pos)))
966 #define bpf_map__for_each bpf_object__for_each_map
967 
968 LIBBPF_API struct bpf_map *
969 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
970 
971 /**
972  * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
973  * BPF map during BPF object load phase.
974  * @param map the BPF map instance
975  * @param autocreate whether to create BPF map during BPF object load
976  * @return 0 on success; -EBUSY if BPF object was already loaded
977  *
978  * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
979  * BPF map. By default, libbpf will attempt to create every single BPF map
980  * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
981  * and fill in map FD in BPF instructions.
982  *
983  * This API allows to opt-out of this process for specific map instance. This
984  * can be useful if host kernel doesn't support such BPF map type or used
985  * combination of flags and user application wants to avoid creating such
986  * a map in the first place. User is still responsible to make sure that their
987  * BPF-side code that expects to use such missing BPF map is recognized by BPF
988  * verifier as dead code, otherwise BPF verifier will reject such BPF program.
989  */
990 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
991 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
992 
993 /**
994  * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach
995  * map during BPF skeleton attach phase.
996  * @param map the BPF map instance
997  * @param autoattach whether to attach map during BPF skeleton attach phase
998  * @return 0 on success; negative error code, otherwise
999  */
1000 LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach);
1001 
1002 /**
1003  * @brief **bpf_map__autoattach()** returns whether BPF map is configured to
1004  * auto-attach during BPF skeleton attach phase.
1005  * @param map the BPF map instance
1006  * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise
1007  */
1008 LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map);
1009 
1010 /**
1011  * @brief **bpf_map__fd()** gets the file descriptor of the passed
1012  * BPF map
1013  * @param map the BPF map instance
1014  * @return the file descriptor; or -EINVAL in case of an error
1015  */
1016 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
1017 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
1018 /* get map name */
1019 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
1020 /* get/set map type */
1021 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
1022 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
1023 /* get/set map size (max_entries) */
1024 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
1025 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
1026 /* get/set map flags */
1027 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
1028 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
1029 /* get/set map NUMA node */
1030 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
1031 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
1032 /* get/set map key size */
1033 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
1034 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
1035 /* get map value size */
1036 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
1037 /**
1038  * @brief **bpf_map__set_value_size()** sets map value size.
1039  * @param map the BPF map instance
1040  * @return 0, on success; negative error, otherwise
1041  *
1042  * There is a special case for maps with associated memory-mapped regions, like
1043  * the global data section maps (bss, data, rodata). When this function is used
1044  * on such a map, the mapped region is resized. Afterward, an attempt is made to
1045  * adjust the corresponding BTF info. This attempt is best-effort and can only
1046  * succeed if the last variable of the data section map is an array. The array
1047  * BTF type is replaced by a new BTF array type with a different length.
1048  * Any previously existing pointers returned from bpf_map__initial_value() or
1049  * corresponding data section skeleton pointer must be reinitialized.
1050  */
1051 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
1052 /* get map key/value BTF type IDs */
1053 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
1054 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
1055 /* get/set map if_index */
1056 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
1057 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
1058 /* get/set map map_extra flags */
1059 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
1060 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
1061 
1062 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
1063 					  const void *data, size_t size);
1064 LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize);
1065 
1066 /**
1067  * @brief **bpf_map__is_internal()** tells the caller whether or not the
1068  * passed map is a special map created by libbpf automatically for things like
1069  * global variables, __ksym externs, Kconfig values, etc
1070  * @param map the bpf_map
1071  * @return true, if the map is an internal map; false, otherwise
1072  */
1073 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
1074 
1075 /**
1076  * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
1077  * BPF map should be pinned. This does not actually create the 'pin'.
1078  * @param map The bpf_map
1079  * @param path The path
1080  * @return 0, on success; negative error, otherwise
1081  */
1082 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
1083 
1084 /**
1085  * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
1086  * BPF map should be pinned.
1087  * @param map The bpf_map
1088  * @return The path string; which can be NULL
1089  */
1090 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
1091 
1092 /**
1093  * @brief **bpf_map__is_pinned()** tells the caller whether or not the
1094  * passed map has been pinned via a 'pin' file.
1095  * @param map The bpf_map
1096  * @return true, if the map is pinned; false, otherwise
1097  */
1098 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
1099 
1100 /**
1101  * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
1102  * for the BPF map. This increments the reference count on the
1103  * BPF map which will keep the BPF map loaded even after the
1104  * userspace process which loaded it has exited.
1105  * @param map The bpf_map to pin
1106  * @param path A file path for the 'pin'
1107  * @return 0, on success; negative error, otherwise
1108  *
1109  * If `path` is NULL the maps `pin_path` attribute will be used. If this is
1110  * also NULL, an error will be returned and the map will not be pinned.
1111  */
1112 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
1113 
1114 /**
1115  * @brief **bpf_map__unpin()** removes the file that serves as a
1116  * 'pin' for the BPF map.
1117  * @param map The bpf_map to unpin
1118  * @param path A file path for the 'pin'
1119  * @return 0, on success; negative error, otherwise
1120  *
1121  * The `path` parameter can be NULL, in which case the `pin_path`
1122  * map attribute is unpinned. If both the `path` parameter and
1123  * `pin_path` map attribute are set, they must be equal.
1124  */
1125 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
1126 
1127 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
1128 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
1129 
1130 /**
1131  * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
1132  * corresponding to provided key.
1133  * @param map BPF map to lookup element in
1134  * @param key pointer to memory containing bytes of the key used for lookup
1135  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1136  * @param value pointer to memory in which looked up value will be stored
1137  * @param value_sz size in byte of value data memory; it has to match BPF map
1138  * definition's **value_size**. For per-CPU BPF maps value size has to be
1139  * a product of BPF map value size and number of possible CPUs in the system
1140  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1141  * per-CPU values value size has to be aligned up to closest 8 bytes for
1142  * alignment reasons, so expected size is: `round_up(value_size, 8)
1143  * * libbpf_num_possible_cpus()`.
1144  * @flags extra flags passed to kernel for this operation
1145  * @return 0, on success; negative error, otherwise
1146  *
1147  * **bpf_map__lookup_elem()** is high-level equivalent of
1148  * **bpf_map_lookup_elem()** API with added check for key and value size.
1149  */
1150 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1151 				    const void *key, size_t key_sz,
1152 				    void *value, size_t value_sz, __u64 flags);
1153 
1154 /**
1155  * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1156  * map that corresponds to provided key.
1157  * @param map BPF map to insert to or update element in
1158  * @param key pointer to memory containing bytes of the key
1159  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1160  * @param value pointer to memory containing bytes of the value
1161  * @param value_sz size in byte of value data memory; it has to match BPF map
1162  * definition's **value_size**. For per-CPU BPF maps value size has to be
1163  * a product of BPF map value size and number of possible CPUs in the system
1164  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1165  * per-CPU values value size has to be aligned up to closest 8 bytes for
1166  * alignment reasons, so expected size is: `round_up(value_size, 8)
1167  * * libbpf_num_possible_cpus()`.
1168  * @flags extra flags passed to kernel for this operation
1169  * @return 0, on success; negative error, otherwise
1170  *
1171  * **bpf_map__update_elem()** is high-level equivalent of
1172  * **bpf_map_update_elem()** API with added check for key and value size.
1173  */
1174 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1175 				    const void *key, size_t key_sz,
1176 				    const void *value, size_t value_sz, __u64 flags);
1177 
1178 /**
1179  * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1180  * corresponds to provided key.
1181  * @param map BPF map to delete element from
1182  * @param key pointer to memory containing bytes of the key
1183  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1184  * @flags extra flags passed to kernel for this operation
1185  * @return 0, on success; negative error, otherwise
1186  *
1187  * **bpf_map__delete_elem()** is high-level equivalent of
1188  * **bpf_map_delete_elem()** API with added check for key size.
1189  */
1190 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1191 				    const void *key, size_t key_sz, __u64 flags);
1192 
1193 /**
1194  * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1195  * corresponding to provided key and atomically delete it afterwards.
1196  * @param map BPF map to lookup element in
1197  * @param key pointer to memory containing bytes of the key used for lookup
1198  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1199  * @param value pointer to memory in which looked up value will be stored
1200  * @param value_sz size in byte of value data memory; it has to match BPF map
1201  * definition's **value_size**. For per-CPU BPF maps value size has to be
1202  * a product of BPF map value size and number of possible CPUs in the system
1203  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1204  * per-CPU values value size has to be aligned up to closest 8 bytes for
1205  * alignment reasons, so expected size is: `round_up(value_size, 8)
1206  * * libbpf_num_possible_cpus()`.
1207  * @flags extra flags passed to kernel for this operation
1208  * @return 0, on success; negative error, otherwise
1209  *
1210  * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1211  * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1212  */
1213 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1214 					       const void *key, size_t key_sz,
1215 					       void *value, size_t value_sz, __u64 flags);
1216 
1217 /**
1218  * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1219  * fetching next key that follows current key.
1220  * @param map BPF map to fetch next key from
1221  * @param cur_key pointer to memory containing bytes of current key or NULL to
1222  * fetch the first key
1223  * @param next_key pointer to memory to write next key into
1224  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1225  * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1226  * negative error, otherwise
1227  *
1228  * **bpf_map__get_next_key()** is high-level equivalent of
1229  * **bpf_map_get_next_key()** API with added check for key size.
1230  */
1231 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1232 				     const void *cur_key, void *next_key, size_t key_sz);
1233 
1234 struct bpf_xdp_set_link_opts {
1235 	size_t sz;
1236 	int old_fd;
1237 	size_t :0;
1238 };
1239 #define bpf_xdp_set_link_opts__last_field old_fd
1240 
1241 struct bpf_xdp_attach_opts {
1242 	size_t sz;
1243 	int old_prog_fd;
1244 	size_t :0;
1245 };
1246 #define bpf_xdp_attach_opts__last_field old_prog_fd
1247 
1248 struct bpf_xdp_query_opts {
1249 	size_t sz;
1250 	__u32 prog_id;		/* output */
1251 	__u32 drv_prog_id;	/* output */
1252 	__u32 hw_prog_id;	/* output */
1253 	__u32 skb_prog_id;	/* output */
1254 	__u8 attach_mode;	/* output */
1255 	__u64 feature_flags;	/* output */
1256 	__u32 xdp_zc_max_segs;	/* output */
1257 	size_t :0;
1258 };
1259 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1260 
1261 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1262 			      const struct bpf_xdp_attach_opts *opts);
1263 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1264 			      const struct bpf_xdp_attach_opts *opts);
1265 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1266 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1267 
1268 /* TC related API */
1269 enum bpf_tc_attach_point {
1270 	BPF_TC_INGRESS = 1 << 0,
1271 	BPF_TC_EGRESS  = 1 << 1,
1272 	BPF_TC_CUSTOM  = 1 << 2,
1273 };
1274 
1275 #define BPF_TC_PARENT(a, b) 	\
1276 	((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1277 
1278 enum bpf_tc_flags {
1279 	BPF_TC_F_REPLACE = 1 << 0,
1280 };
1281 
1282 struct bpf_tc_hook {
1283 	size_t sz;
1284 	int ifindex;
1285 	enum bpf_tc_attach_point attach_point;
1286 	__u32 parent;
1287 	size_t :0;
1288 };
1289 #define bpf_tc_hook__last_field parent
1290 
1291 struct bpf_tc_opts {
1292 	size_t sz;
1293 	int prog_fd;
1294 	__u32 flags;
1295 	__u32 prog_id;
1296 	__u32 handle;
1297 	__u32 priority;
1298 	size_t :0;
1299 };
1300 #define bpf_tc_opts__last_field priority
1301 
1302 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1303 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1304 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1305 			     struct bpf_tc_opts *opts);
1306 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1307 			     const struct bpf_tc_opts *opts);
1308 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1309 			    struct bpf_tc_opts *opts);
1310 
1311 /* Ring buffer APIs */
1312 struct ring_buffer;
1313 struct ring;
1314 struct user_ring_buffer;
1315 
1316 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1317 
1318 struct ring_buffer_opts {
1319 	size_t sz; /* size of this struct, for forward/backward compatibility */
1320 };
1321 
1322 #define ring_buffer_opts__last_field sz
1323 
1324 LIBBPF_API struct ring_buffer *
1325 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1326 		 const struct ring_buffer_opts *opts);
1327 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1328 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1329 				ring_buffer_sample_fn sample_cb, void *ctx);
1330 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1331 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1332 LIBBPF_API int ring_buffer__consume_n(struct ring_buffer *rb, size_t n);
1333 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1334 
1335 /**
1336  * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given
1337  * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance.
1338  *
1339  * @param rb A ringbuffer manager object.
1340  * @param idx An index into the ringbuffers contained within the ringbuffer
1341  * manager object. The index is 0-based and corresponds to the order in which
1342  * ring_buffer__add was called.
1343  * @return A ringbuffer object on success; NULL and errno set if the index is
1344  * invalid.
1345  */
1346 LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb,
1347 					  unsigned int idx);
1348 
1349 /**
1350  * @brief **ring__consumer_pos()** returns the current consumer position in the
1351  * given ringbuffer.
1352  *
1353  * @param r A ringbuffer object.
1354  * @return The current consumer position.
1355  */
1356 LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r);
1357 
1358 /**
1359  * @brief **ring__producer_pos()** returns the current producer position in the
1360  * given ringbuffer.
1361  *
1362  * @param r A ringbuffer object.
1363  * @return The current producer position.
1364  */
1365 LIBBPF_API unsigned long ring__producer_pos(const struct ring *r);
1366 
1367 /**
1368  * @brief **ring__avail_data_size()** returns the number of bytes in the
1369  * ringbuffer not yet consumed. This has no locking associated with it, so it
1370  * can be inaccurate if operations are ongoing while this is called. However, it
1371  * should still show the correct trend over the long-term.
1372  *
1373  * @param r A ringbuffer object.
1374  * @return The number of bytes not yet consumed.
1375  */
1376 LIBBPF_API size_t ring__avail_data_size(const struct ring *r);
1377 
1378 /**
1379  * @brief **ring__size()** returns the total size of the ringbuffer's map data
1380  * area (excluding special producer/consumer pages). Effectively this gives the
1381  * amount of usable bytes of data inside the ringbuffer.
1382  *
1383  * @param r A ringbuffer object.
1384  * @return The total size of the ringbuffer map data area.
1385  */
1386 LIBBPF_API size_t ring__size(const struct ring *r);
1387 
1388 /**
1389  * @brief **ring__map_fd()** returns the file descriptor underlying the given
1390  * ringbuffer.
1391  *
1392  * @param r A ringbuffer object.
1393  * @return The underlying ringbuffer file descriptor
1394  */
1395 LIBBPF_API int ring__map_fd(const struct ring *r);
1396 
1397 /**
1398  * @brief **ring__consume()** consumes available ringbuffer data without event
1399  * polling.
1400  *
1401  * @param r A ringbuffer object.
1402  * @return The number of records consumed (or INT_MAX, whichever is less), or
1403  * a negative number if any of the callbacks return an error.
1404  */
1405 LIBBPF_API int ring__consume(struct ring *r);
1406 
1407 /**
1408  * @brief **ring__consume_n()** consumes up to a requested amount of items from
1409  * a ringbuffer without event polling.
1410  *
1411  * @param r A ringbuffer object.
1412  * @param n Maximum amount of items to consume.
1413  * @return The number of items consumed, or a negative number if any of the
1414  * callbacks return an error.
1415  */
1416 LIBBPF_API int ring__consume_n(struct ring *r, size_t n);
1417 
1418 struct user_ring_buffer_opts {
1419 	size_t sz; /* size of this struct, for forward/backward compatibility */
1420 };
1421 
1422 #define user_ring_buffer_opts__last_field sz
1423 
1424 /**
1425  * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1426  * buffer.
1427  *
1428  * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1429  * @param opts Options for how the ring buffer should be created.
1430  * @return A user ring buffer on success; NULL and errno being set on a
1431  * failure.
1432  */
1433 LIBBPF_API struct user_ring_buffer *
1434 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1435 
1436 /**
1437  * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1438  * user ring buffer.
1439  * @param rb A pointer to a user ring buffer.
1440  * @param size The size of the sample, in bytes.
1441  * @return A pointer to an 8-byte aligned reserved region of the user ring
1442  * buffer; NULL, and errno being set if a sample could not be reserved.
1443  *
1444  * This function is *not* thread safe, and callers must synchronize accessing
1445  * this function if there are multiple producers.  If a size is requested that
1446  * is larger than the size of the entire ring buffer, errno will be set to
1447  * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1448  * but currently does not have enough space, errno is set to ENOSPC and NULL is
1449  * returned.
1450  *
1451  * After initializing the sample, callers must invoke
1452  * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1453  * the sample must be freed with **user_ring_buffer__discard()**.
1454  */
1455 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1456 
1457 /**
1458  * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1459  * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1460  * available.
1461  * @param rb The user ring buffer.
1462  * @param size The size of the sample, in bytes.
1463  * @param timeout_ms The amount of time, in milliseconds, for which the caller
1464  * should block when waiting for a sample. -1 causes the caller to block
1465  * indefinitely.
1466  * @return A pointer to an 8-byte aligned reserved region of the user ring
1467  * buffer; NULL, and errno being set if a sample could not be reserved.
1468  *
1469  * This function is *not* thread safe, and callers must synchronize
1470  * accessing this function if there are multiple producers
1471  *
1472  * If **timeout_ms** is -1, the function will block indefinitely until a sample
1473  * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1474  * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1475  * will occur and the function will return immediately after attempting to
1476  * reserve a sample.
1477  *
1478  * If **size** is larger than the size of the entire ring buffer, errno is set
1479  * to E2BIG and NULL is returned. If the ring buffer could accommodate
1480  * **size**, but currently does not have enough space, the caller will block
1481  * until at most **timeout_ms** has elapsed. If insufficient space is available
1482  * at that time, errno is set to ENOSPC, and NULL is returned.
1483  *
1484  * The kernel guarantees that it will wake up this thread to check if
1485  * sufficient space is available in the ring buffer at least once per
1486  * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1487  * least one sample is consumed, and the BPF program did not invoke the
1488  * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1489  * kernel does not guarantee this. If the helper function is invoked with
1490  * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1491  * consumed.
1492  *
1493  * When a sample of size **size** is found within **timeout_ms**, a pointer to
1494  * the sample is returned. After initializing the sample, callers must invoke
1495  * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1496  * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1497  */
1498 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1499 						    __u32 size,
1500 						    int timeout_ms);
1501 
1502 /**
1503  * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1504  * into the ring buffer.
1505  * @param rb The user ring buffer.
1506  * @param sample A reserved sample.
1507  *
1508  * It is not necessary to synchronize amongst multiple producers when invoking
1509  * this function.
1510  */
1511 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1512 
1513 /**
1514  * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1515  * @param rb The user ring buffer.
1516  * @param sample A reserved sample.
1517  *
1518  * It is not necessary to synchronize amongst multiple producers when invoking
1519  * this function.
1520  */
1521 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1522 
1523 /**
1524  * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1525  * created with **user_ring_buffer__new()**.
1526  * @param rb The user ring buffer being freed.
1527  */
1528 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1529 
1530 /* Perf buffer APIs */
1531 struct perf_buffer;
1532 
1533 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1534 				      void *data, __u32 size);
1535 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1536 
1537 /* common use perf buffer options */
1538 struct perf_buffer_opts {
1539 	size_t sz;
1540 	__u32 sample_period;
1541 	size_t :0;
1542 };
1543 #define perf_buffer_opts__last_field sample_period
1544 
1545 /**
1546  * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1547  * BPF_PERF_EVENT_ARRAY map
1548  * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1549  * code to send data over to user-space
1550  * @param page_cnt number of memory pages allocated for each per-CPU buffer
1551  * @param sample_cb function called on each received data record
1552  * @param lost_cb function called when record loss has occurred
1553  * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1554  * @return a new instance of struct perf_buffer on success, NULL on error with
1555  * *errno* containing an error code
1556  */
1557 LIBBPF_API struct perf_buffer *
1558 perf_buffer__new(int map_fd, size_t page_cnt,
1559 		 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1560 		 const struct perf_buffer_opts *opts);
1561 
1562 enum bpf_perf_event_ret {
1563 	LIBBPF_PERF_EVENT_DONE	= 0,
1564 	LIBBPF_PERF_EVENT_ERROR	= -1,
1565 	LIBBPF_PERF_EVENT_CONT	= -2,
1566 };
1567 
1568 struct perf_event_header;
1569 
1570 typedef enum bpf_perf_event_ret
1571 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1572 
1573 /* raw perf buffer options, giving most power and control */
1574 struct perf_buffer_raw_opts {
1575 	size_t sz;
1576 	long :0;
1577 	long :0;
1578 	/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1579 	 * max_entries of given PERF_EVENT_ARRAY map)
1580 	 */
1581 	int cpu_cnt;
1582 	/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1583 	int *cpus;
1584 	/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1585 	int *map_keys;
1586 };
1587 #define perf_buffer_raw_opts__last_field map_keys
1588 
1589 struct perf_event_attr;
1590 
1591 LIBBPF_API struct perf_buffer *
1592 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1593 		     perf_buffer_event_fn event_cb, void *ctx,
1594 		     const struct perf_buffer_raw_opts *opts);
1595 
1596 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1597 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1598 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1599 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1600 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1601 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1602 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1603 /**
1604  * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1605  * memory region of the ring buffer.
1606  * This ring buffer can be used to implement a custom events consumer.
1607  * The ring buffer starts with the *struct perf_event_mmap_page*, which
1608  * holds the ring buffer management fields, when accessing the header
1609  * structure it's important to be SMP aware.
1610  * You can refer to *perf_event_read_simple* for a simple example.
1611  * @param pb the perf buffer structure
1612  * @param buf_idx the buffer index to retrieve
1613  * @param buf (out) gets the base pointer of the mmap()'ed memory
1614  * @param buf_size (out) gets the size of the mmap()'ed region
1615  * @return 0 on success, negative error code for failure
1616  */
1617 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1618 				   size_t *buf_size);
1619 
1620 struct bpf_prog_linfo;
1621 struct bpf_prog_info;
1622 
1623 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1624 LIBBPF_API struct bpf_prog_linfo *
1625 bpf_prog_linfo__new(const struct bpf_prog_info *info);
1626 LIBBPF_API const struct bpf_line_info *
1627 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1628 				__u64 addr, __u32 func_idx, __u32 nr_skip);
1629 LIBBPF_API const struct bpf_line_info *
1630 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1631 		      __u32 insn_off, __u32 nr_skip);
1632 
1633 /*
1634  * Probe for supported system features
1635  *
1636  * Note that running many of these probes in a short amount of time can cause
1637  * the kernel to reach the maximal size of lockable memory allowed for the
1638  * user, causing subsequent probes to fail. In this case, the caller may want
1639  * to adjust that limit with setrlimit().
1640  */
1641 
1642 /**
1643  * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1644  * BPF programs of a given type.
1645  * @param prog_type BPF program type to detect kernel support for
1646  * @param opts reserved for future extensibility, should be NULL
1647  * @return 1, if given program type is supported; 0, if given program type is
1648  * not supported; negative error code if feature detection failed or can't be
1649  * performed
1650  *
1651  * Make sure the process has required set of CAP_* permissions (or runs as
1652  * root) when performing feature checking.
1653  */
1654 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1655 /**
1656  * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1657  * BPF maps of a given type.
1658  * @param map_type BPF map type to detect kernel support for
1659  * @param opts reserved for future extensibility, should be NULL
1660  * @return 1, if given map type is supported; 0, if given map type is
1661  * not supported; negative error code if feature detection failed or can't be
1662  * performed
1663  *
1664  * Make sure the process has required set of CAP_* permissions (or runs as
1665  * root) when performing feature checking.
1666  */
1667 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1668 /**
1669  * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1670  * use of a given BPF helper from specified BPF program type.
1671  * @param prog_type BPF program type used to check the support of BPF helper
1672  * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1673  * @param opts reserved for future extensibility, should be NULL
1674  * @return 1, if given combination of program type and helper is supported; 0,
1675  * if the combination is not supported; negative error code if feature
1676  * detection for provided input arguments failed or can't be performed
1677  *
1678  * Make sure the process has required set of CAP_* permissions (or runs as
1679  * root) when performing feature checking.
1680  */
1681 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1682 				       enum bpf_func_id helper_id, const void *opts);
1683 
1684 /**
1685  * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1686  * number of possible CPUs that the host kernel supports and expects.
1687  * @return number of possible CPUs; or error code on failure
1688  *
1689  * Example usage:
1690  *
1691  *     int ncpus = libbpf_num_possible_cpus();
1692  *     if (ncpus < 0) {
1693  *          // error handling
1694  *     }
1695  *     long values[ncpus];
1696  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1697  */
1698 LIBBPF_API int libbpf_num_possible_cpus(void);
1699 
1700 struct bpf_map_skeleton {
1701 	const char *name;
1702 	struct bpf_map **map;
1703 	void **mmaped;
1704 	struct bpf_link **link;
1705 };
1706 
1707 struct bpf_prog_skeleton {
1708 	const char *name;
1709 	struct bpf_program **prog;
1710 	struct bpf_link **link;
1711 };
1712 
1713 struct bpf_object_skeleton {
1714 	size_t sz; /* size of this struct, for forward/backward compatibility */
1715 
1716 	const char *name;
1717 	const void *data;
1718 	size_t data_sz;
1719 
1720 	struct bpf_object **obj;
1721 
1722 	int map_cnt;
1723 	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1724 	struct bpf_map_skeleton *maps;
1725 
1726 	int prog_cnt;
1727 	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1728 	struct bpf_prog_skeleton *progs;
1729 };
1730 
1731 LIBBPF_API int
1732 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1733 			  const struct bpf_object_open_opts *opts);
1734 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1735 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1736 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1737 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1738 
1739 struct bpf_var_skeleton {
1740 	const char *name;
1741 	struct bpf_map **map;
1742 	void **addr;
1743 };
1744 
1745 struct bpf_object_subskeleton {
1746 	size_t sz; /* size of this struct, for forward/backward compatibility */
1747 
1748 	const struct bpf_object *obj;
1749 
1750 	int map_cnt;
1751 	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1752 	struct bpf_map_skeleton *maps;
1753 
1754 	int prog_cnt;
1755 	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1756 	struct bpf_prog_skeleton *progs;
1757 
1758 	int var_cnt;
1759 	int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1760 	struct bpf_var_skeleton *vars;
1761 };
1762 
1763 LIBBPF_API int
1764 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1765 LIBBPF_API void
1766 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1767 
1768 struct gen_loader_opts {
1769 	size_t sz; /* size of this struct, for forward/backward compatibility */
1770 	const char *data;
1771 	const char *insns;
1772 	__u32 data_sz;
1773 	__u32 insns_sz;
1774 };
1775 
1776 #define gen_loader_opts__last_field insns_sz
1777 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1778 				      struct gen_loader_opts *opts);
1779 
1780 enum libbpf_tristate {
1781 	TRI_NO = 0,
1782 	TRI_YES = 1,
1783 	TRI_MODULE = 2,
1784 };
1785 
1786 struct bpf_linker_opts {
1787 	/* size of this struct, for forward/backward compatibility */
1788 	size_t sz;
1789 };
1790 #define bpf_linker_opts__last_field sz
1791 
1792 struct bpf_linker_file_opts {
1793 	/* size of this struct, for forward/backward compatibility */
1794 	size_t sz;
1795 };
1796 #define bpf_linker_file_opts__last_field sz
1797 
1798 struct bpf_linker;
1799 
1800 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1801 LIBBPF_API struct bpf_linker *bpf_linker__new_fd(int fd, struct bpf_linker_opts *opts);
1802 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1803 				    const char *filename,
1804 				    const struct bpf_linker_file_opts *opts);
1805 LIBBPF_API int bpf_linker__add_fd(struct bpf_linker *linker, int fd,
1806 				  const struct bpf_linker_file_opts *opts);
1807 LIBBPF_API int bpf_linker__add_buf(struct bpf_linker *linker, void *buf, size_t buf_sz,
1808 				   const struct bpf_linker_file_opts *opts);
1809 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1810 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1811 
1812 /*
1813  * Custom handling of BPF program's SEC() definitions
1814  */
1815 
1816 struct bpf_prog_load_opts; /* defined in bpf.h */
1817 
1818 /* Called during bpf_object__open() for each recognized BPF program. Callback
1819  * can use various bpf_program__set_*() setters to adjust whatever properties
1820  * are necessary.
1821  */
1822 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1823 
1824 /* Called right before libbpf performs bpf_prog_load() to load BPF program
1825  * into the kernel. Callback can adjust opts as necessary.
1826  */
1827 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1828 					     struct bpf_prog_load_opts *opts, long cookie);
1829 
1830 /* Called during skeleton attach or through bpf_program__attach(). If
1831  * auto-attach is not supported, callback should return 0 and set link to
1832  * NULL (it's not considered an error during skeleton attach, but it will be
1833  * an error for bpf_program__attach() calls). On error, error should be
1834  * returned directly and link set to NULL. On success, return 0 and set link
1835  * to a valid struct bpf_link.
1836  */
1837 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1838 				       struct bpf_link **link);
1839 
1840 struct libbpf_prog_handler_opts {
1841 	/* size of this struct, for forward/backward compatibility */
1842 	size_t sz;
1843 	/* User-provided value that is passed to prog_setup_fn,
1844 	 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1845 	 * register one set of callbacks for multiple SEC() definitions and
1846 	 * still be able to distinguish them, if necessary. For example,
1847 	 * libbpf itself is using this to pass necessary flags (e.g.,
1848 	 * sleepable flag) to a common internal SEC() handler.
1849 	 */
1850 	long cookie;
1851 	/* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1852 	 * Callback is optional, pass NULL if it's not necessary.
1853 	 */
1854 	libbpf_prog_setup_fn_t prog_setup_fn;
1855 	/* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1856 	 * Callback is optional, pass NULL if it's not necessary.
1857 	 */
1858 	libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1859 	/* BPF program attach callback (see libbpf_prog_attach_fn_t).
1860 	 * Callback is optional, pass NULL if it's not necessary.
1861 	 */
1862 	libbpf_prog_attach_fn_t prog_attach_fn;
1863 };
1864 #define libbpf_prog_handler_opts__last_field prog_attach_fn
1865 
1866 /**
1867  * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1868  * SEC() handler.
1869  * @param sec section prefix for which custom handler is registered
1870  * @param prog_type BPF program type associated with specified section
1871  * @param exp_attach_type Expected BPF attach type associated with specified section
1872  * @param opts optional cookie, callbacks, and other extra options
1873  * @return Non-negative handler ID is returned on success. This handler ID has
1874  * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1875  * custom handler. Negative error code is returned on error.
1876  *
1877  * *sec* defines which SEC() definitions are handled by this custom handler
1878  * registration. *sec* can have few different forms:
1879  *   - if *sec* is just a plain string (e.g., "abc"), it will match only
1880  *   SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1881  *   in an error;
1882  *   - if *sec* is of the form "abc/", proper SEC() form is
1883  *   SEC("abc/something"), where acceptable "something" should be checked by
1884  *   *prog_init_fn* callback, if there are additional restrictions;
1885  *   - if *sec* is of the form "abc+", it will successfully match both
1886  *   SEC("abc") and SEC("abc/whatever") forms;
1887  *   - if *sec* is NULL, custom handler is registered for any BPF program that
1888  *   doesn't match any of the registered (custom or libbpf's own) SEC()
1889  *   handlers. There could be only one such generic custom handler registered
1890  *   at any given time.
1891  *
1892  * All custom handlers (except the one with *sec* == NULL) are processed
1893  * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1894  * SEC() handlers by registering custom ones for the same section prefix
1895  * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1896  * handler).
1897  *
1898  * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1899  * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1900  * to ensure synchronization if there is a risk of running this API from
1901  * multiple threads simultaneously.
1902  */
1903 LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1904 					    enum bpf_prog_type prog_type,
1905 					    enum bpf_attach_type exp_attach_type,
1906 					    const struct libbpf_prog_handler_opts *opts);
1907 /**
1908  * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1909  * custom BPF program SEC() handler.
1910  * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1911  * after successful registration
1912  * @return 0 on success, negative error code if handler isn't found
1913  *
1914  * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1915  * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1916  * to ensure synchronization if there is a risk of running this API from
1917  * multiple threads simultaneously.
1918  */
1919 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1920 
1921 #ifdef __cplusplus
1922 } /* extern "C" */
1923 #endif
1924 
1925 #endif /* __LIBBPF_LIBBPF_H */
1926