xref: /linux/tools/lib/bpf/libbpf.h (revision ea02a946)
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 	size_t :0;
556 };
557 
558 #define bpf_kprobe_multi_opts__last_field session
559 
560 LIBBPF_API struct bpf_link *
561 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
562 				      const char *pattern,
563 				      const struct bpf_kprobe_multi_opts *opts);
564 
565 struct bpf_uprobe_multi_opts {
566 	/* size of this struct, for forward/backward compatibility */
567 	size_t sz;
568 	/* array of function symbols to attach to */
569 	const char **syms;
570 	/* array of function addresses to attach to */
571 	const unsigned long *offsets;
572 	/* optional, array of associated ref counter offsets */
573 	const unsigned long *ref_ctr_offsets;
574 	/* optional, array of associated BPF cookies */
575 	const __u64 *cookies;
576 	/* number of elements in syms/addrs/cookies arrays */
577 	size_t cnt;
578 	/* create return uprobes */
579 	bool retprobe;
580 	size_t :0;
581 };
582 
583 #define bpf_uprobe_multi_opts__last_field retprobe
584 
585 /**
586  * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
587  * to multiple uprobes with uprobe_multi link.
588  *
589  * User can specify 2 mutually exclusive set of inputs:
590  *
591  *   1) use only path/func_pattern/pid arguments
592  *
593  *   2) use path/pid with allowed combinations of
594  *      syms/offsets/ref_ctr_offsets/cookies/cnt
595  *
596  *      - syms and offsets are mutually exclusive
597  *      - ref_ctr_offsets and cookies are optional
598  *
599  *
600  * @param prog BPF program to attach
601  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
602  * -1 for all processes
603  * @param binary_path Path to binary
604  * @param func_pattern Regular expression to specify functions to attach
605  * BPF program to
606  * @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
607  * @return 0, on success; negative error code, otherwise
608  */
609 LIBBPF_API struct bpf_link *
610 bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
611 				 pid_t pid,
612 				 const char *binary_path,
613 				 const char *func_pattern,
614 				 const struct bpf_uprobe_multi_opts *opts);
615 
616 struct bpf_ksyscall_opts {
617 	/* size of this struct, for forward/backward compatibility */
618 	size_t sz;
619 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
620 	__u64 bpf_cookie;
621 	/* attach as return probe? */
622 	bool retprobe;
623 	size_t :0;
624 };
625 #define bpf_ksyscall_opts__last_field retprobe
626 
627 /**
628  * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
629  * to kernel syscall handler of a specified syscall. Optionally it's possible
630  * to request to install retprobe that will be triggered at syscall exit. It's
631  * also possible to associate BPF cookie (though options).
632  *
633  * Libbpf automatically will determine correct full kernel function name,
634  * which depending on system architecture and kernel version/configuration
635  * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
636  * attach specified program using kprobe/kretprobe mechanism.
637  *
638  * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
639  * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
640  *
641  * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
642  * not handle all the calling convention quirks for mmap(), clone() and compat
643  * syscalls. It also only attaches to "native" syscall interfaces. If host
644  * system supports compat syscalls or defines 32-bit syscalls in 64-bit
645  * kernel, such syscall interfaces won't be attached to by libbpf.
646  *
647  * These limitations may or may not change in the future. Therefore it is
648  * recommended to use SEC("kprobe") for these syscalls or if working with
649  * compat and 32-bit interfaces is required.
650  *
651  * @param prog BPF program to attach
652  * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
653  * @param opts Additional options (see **struct bpf_ksyscall_opts**)
654  * @return Reference to the newly created BPF link; or NULL is returned on
655  * error, error code is stored in errno
656  */
657 LIBBPF_API struct bpf_link *
658 bpf_program__attach_ksyscall(const struct bpf_program *prog,
659 			     const char *syscall_name,
660 			     const struct bpf_ksyscall_opts *opts);
661 
662 struct bpf_uprobe_opts {
663 	/* size of this struct, for forward/backward compatibility */
664 	size_t sz;
665 	/* offset of kernel reference counted USDT semaphore, added in
666 	 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
667 	 */
668 	size_t ref_ctr_offset;
669 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
670 	__u64 bpf_cookie;
671 	/* uprobe is return probe, invoked at function return time */
672 	bool retprobe;
673 	/* Function name to attach to.  Could be an unqualified ("abc") or library-qualified
674 	 * "abc@LIBXYZ" name.  To specify function entry, func_name should be set while
675 	 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0.  To trace an
676 	 * offset within a function, specify func_name and use func_offset argument to specify
677 	 * offset within the function.  Shared library functions must specify the shared library
678 	 * binary_path.
679 	 */
680 	const char *func_name;
681 	/* uprobe attach mode */
682 	enum probe_attach_mode attach_mode;
683 	size_t :0;
684 };
685 #define bpf_uprobe_opts__last_field attach_mode
686 
687 /**
688  * @brief **bpf_program__attach_uprobe()** attaches a BPF program
689  * to the userspace function which is found by binary path and
690  * offset. You can optionally specify a particular process to attach
691  * to. You can also optionally attach the program to the function
692  * exit instead of entry.
693  *
694  * @param prog BPF program to attach
695  * @param retprobe Attach to function exit
696  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
697  * -1 for all processes
698  * @param binary_path Path to binary that contains the function symbol
699  * @param func_offset Offset within the binary of the function symbol
700  * @return Reference to the newly created BPF link; or NULL is returned on error,
701  * error code is stored in errno
702  */
703 LIBBPF_API struct bpf_link *
704 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
705 			   pid_t pid, const char *binary_path,
706 			   size_t func_offset);
707 
708 /**
709  * @brief **bpf_program__attach_uprobe_opts()** is just like
710  * bpf_program__attach_uprobe() except with a options struct
711  * for various configurations.
712  *
713  * @param prog BPF program to attach
714  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
715  * -1 for all processes
716  * @param binary_path Path to binary that contains the function symbol
717  * @param func_offset Offset within the binary of the function symbol
718  * @param opts Options for altering program attachment
719  * @return Reference to the newly created BPF link; or NULL is returned on error,
720  * error code is stored in errno
721  */
722 LIBBPF_API struct bpf_link *
723 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
724 				const char *binary_path, size_t func_offset,
725 				const struct bpf_uprobe_opts *opts);
726 
727 struct bpf_usdt_opts {
728 	/* size of this struct, for forward/backward compatibility */
729 	size_t sz;
730 	/* custom user-provided value accessible through usdt_cookie() */
731 	__u64 usdt_cookie;
732 	size_t :0;
733 };
734 #define bpf_usdt_opts__last_field usdt_cookie
735 
736 /**
737  * @brief **bpf_program__attach_usdt()** is just like
738  * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
739  * Statically Defined Tracepoint) attachment, instead of attaching to
740  * user-space function entry or exit.
741  *
742  * @param prog BPF program to attach
743  * @param pid Process ID to attach the uprobe to, 0 for self (own process),
744  * -1 for all processes
745  * @param binary_path Path to binary that contains provided USDT probe
746  * @param usdt_provider USDT provider name
747  * @param usdt_name USDT probe name
748  * @param opts Options for altering program attachment
749  * @return Reference to the newly created BPF link; or NULL is returned on error,
750  * error code is stored in errno
751  */
752 LIBBPF_API struct bpf_link *
753 bpf_program__attach_usdt(const struct bpf_program *prog,
754 			 pid_t pid, const char *binary_path,
755 			 const char *usdt_provider, const char *usdt_name,
756 			 const struct bpf_usdt_opts *opts);
757 
758 struct bpf_tracepoint_opts {
759 	/* size of this struct, for forward/backward compatibility */
760 	size_t sz;
761 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
762 	__u64 bpf_cookie;
763 };
764 #define bpf_tracepoint_opts__last_field bpf_cookie
765 
766 LIBBPF_API struct bpf_link *
767 bpf_program__attach_tracepoint(const struct bpf_program *prog,
768 			       const char *tp_category,
769 			       const char *tp_name);
770 LIBBPF_API struct bpf_link *
771 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
772 				    const char *tp_category,
773 				    const char *tp_name,
774 				    const struct bpf_tracepoint_opts *opts);
775 
776 struct bpf_raw_tracepoint_opts {
777 	size_t sz; /* size of this struct for forward/backward compatibility */
778 	__u64 cookie;
779 	size_t :0;
780 };
781 #define bpf_raw_tracepoint_opts__last_field cookie
782 
783 LIBBPF_API struct bpf_link *
784 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
785 				   const char *tp_name);
786 LIBBPF_API struct bpf_link *
787 bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog,
788 					const char *tp_name,
789 					struct bpf_raw_tracepoint_opts *opts);
790 
791 struct bpf_trace_opts {
792 	/* size of this struct, for forward/backward compatibility */
793 	size_t sz;
794 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
795 	__u64 cookie;
796 };
797 #define bpf_trace_opts__last_field cookie
798 
799 LIBBPF_API struct bpf_link *
800 bpf_program__attach_trace(const struct bpf_program *prog);
801 LIBBPF_API struct bpf_link *
802 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
803 
804 LIBBPF_API struct bpf_link *
805 bpf_program__attach_lsm(const struct bpf_program *prog);
806 LIBBPF_API struct bpf_link *
807 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
808 LIBBPF_API struct bpf_link *
809 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
810 LIBBPF_API struct bpf_link *
811 bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd);
812 LIBBPF_API struct bpf_link *
813 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
814 LIBBPF_API struct bpf_link *
815 bpf_program__attach_freplace(const struct bpf_program *prog,
816 			     int target_fd, const char *attach_func_name);
817 
818 struct bpf_netfilter_opts {
819 	/* size of this struct, for forward/backward compatibility */
820 	size_t sz;
821 
822 	__u32 pf;
823 	__u32 hooknum;
824 	__s32 priority;
825 	__u32 flags;
826 };
827 #define bpf_netfilter_opts__last_field flags
828 
829 LIBBPF_API struct bpf_link *
830 bpf_program__attach_netfilter(const struct bpf_program *prog,
831 			      const struct bpf_netfilter_opts *opts);
832 
833 struct bpf_tcx_opts {
834 	/* size of this struct, for forward/backward compatibility */
835 	size_t sz;
836 	__u32 flags;
837 	__u32 relative_fd;
838 	__u32 relative_id;
839 	__u64 expected_revision;
840 	size_t :0;
841 };
842 #define bpf_tcx_opts__last_field expected_revision
843 
844 LIBBPF_API struct bpf_link *
845 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
846 			const struct bpf_tcx_opts *opts);
847 
848 struct bpf_netkit_opts {
849 	/* size of this struct, for forward/backward compatibility */
850 	size_t sz;
851 	__u32 flags;
852 	__u32 relative_fd;
853 	__u32 relative_id;
854 	__u64 expected_revision;
855 	size_t :0;
856 };
857 #define bpf_netkit_opts__last_field expected_revision
858 
859 LIBBPF_API struct bpf_link *
860 bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
861 			   const struct bpf_netkit_opts *opts);
862 
863 struct bpf_map;
864 
865 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
866 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
867 
868 struct bpf_iter_attach_opts {
869 	size_t sz; /* size of this struct for forward/backward compatibility */
870 	union bpf_iter_link_info *link_info;
871 	__u32 link_info_len;
872 };
873 #define bpf_iter_attach_opts__last_field link_info_len
874 
875 LIBBPF_API struct bpf_link *
876 bpf_program__attach_iter(const struct bpf_program *prog,
877 			 const struct bpf_iter_attach_opts *opts);
878 
879 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
880 
881 /**
882  * @brief **bpf_program__set_type()** sets the program
883  * type of the passed BPF program.
884  * @param prog BPF program to set the program type for
885  * @param type program type to set the BPF map to have
886  * @return error code; or 0 if no error. An error occurs
887  * if the object is already loaded.
888  *
889  * This must be called before the BPF object is loaded,
890  * otherwise it has no effect and an error is returned.
891  */
892 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
893 				     enum bpf_prog_type type);
894 
895 LIBBPF_API enum bpf_attach_type
896 bpf_program__expected_attach_type(const struct bpf_program *prog);
897 
898 /**
899  * @brief **bpf_program__set_expected_attach_type()** sets the
900  * attach type of the passed BPF program. This is used for
901  * auto-detection of attachment when programs are loaded.
902  * @param prog BPF program to set the attach type for
903  * @param type attach type to set the BPF map to have
904  * @return error code; or 0 if no error. An error occurs
905  * if the object is already loaded.
906  *
907  * This must be called before the BPF object is loaded,
908  * otherwise it has no effect and an error is returned.
909  */
910 LIBBPF_API int
911 bpf_program__set_expected_attach_type(struct bpf_program *prog,
912 				      enum bpf_attach_type type);
913 
914 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
915 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
916 
917 /* Per-program log level and log buffer getters/setters.
918  * See bpf_object_open_opts comments regarding log_level and log_buf
919  * interactions.
920  */
921 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
922 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
923 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
924 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
925 
926 /**
927  * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
928  * for supported BPF program types:
929  *   - BTF-aware raw tracepoints (tp_btf);
930  *   - fentry/fexit/fmod_ret;
931  *   - lsm;
932  *   - freplace.
933  * @param prog BPF program to set the attach type for
934  * @param type attach type to set the BPF map to have
935  * @return error code; or 0 if no error occurred.
936  */
937 LIBBPF_API int
938 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
939 			       const char *attach_func_name);
940 
941 /**
942  * @brief **bpf_object__find_map_by_name()** returns BPF map of
943  * the given name, if it exists within the passed BPF object
944  * @param obj BPF object
945  * @param name name of the BPF map
946  * @return BPF map instance, if such map exists within the BPF object;
947  * or NULL otherwise.
948  */
949 LIBBPF_API struct bpf_map *
950 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
951 
952 LIBBPF_API int
953 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
954 
955 LIBBPF_API struct bpf_map *
956 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
957 
958 #define bpf_object__for_each_map(pos, obj)		\
959 	for ((pos) = bpf_object__next_map((obj), NULL);	\
960 	     (pos) != NULL;				\
961 	     (pos) = bpf_object__next_map((obj), (pos)))
962 #define bpf_map__for_each bpf_object__for_each_map
963 
964 LIBBPF_API struct bpf_map *
965 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
966 
967 /**
968  * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
969  * BPF map during BPF object load phase.
970  * @param map the BPF map instance
971  * @param autocreate whether to create BPF map during BPF object load
972  * @return 0 on success; -EBUSY if BPF object was already loaded
973  *
974  * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
975  * BPF map. By default, libbpf will attempt to create every single BPF map
976  * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
977  * and fill in map FD in BPF instructions.
978  *
979  * This API allows to opt-out of this process for specific map instance. This
980  * can be useful if host kernel doesn't support such BPF map type or used
981  * combination of flags and user application wants to avoid creating such
982  * a map in the first place. User is still responsible to make sure that their
983  * BPF-side code that expects to use such missing BPF map is recognized by BPF
984  * verifier as dead code, otherwise BPF verifier will reject such BPF program.
985  */
986 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
987 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
988 
989 /**
990  * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach
991  * map during BPF skeleton attach phase.
992  * @param map the BPF map instance
993  * @param autoattach whether to attach map during BPF skeleton attach phase
994  * @return 0 on success; negative error code, otherwise
995  */
996 LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach);
997 
998 /**
999  * @brief **bpf_map__autoattach()** returns whether BPF map is configured to
1000  * auto-attach during BPF skeleton attach phase.
1001  * @param map the BPF map instance
1002  * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise
1003  */
1004 LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map);
1005 
1006 /**
1007  * @brief **bpf_map__fd()** gets the file descriptor of the passed
1008  * BPF map
1009  * @param map the BPF map instance
1010  * @return the file descriptor; or -EINVAL in case of an error
1011  */
1012 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
1013 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
1014 /* get map name */
1015 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
1016 /* get/set map type */
1017 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
1018 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
1019 /* get/set map size (max_entries) */
1020 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
1021 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
1022 /* get/set map flags */
1023 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
1024 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
1025 /* get/set map NUMA node */
1026 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
1027 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
1028 /* get/set map key size */
1029 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
1030 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
1031 /* get map value size */
1032 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
1033 /**
1034  * @brief **bpf_map__set_value_size()** sets map value size.
1035  * @param map the BPF map instance
1036  * @return 0, on success; negative error, otherwise
1037  *
1038  * There is a special case for maps with associated memory-mapped regions, like
1039  * the global data section maps (bss, data, rodata). When this function is used
1040  * on such a map, the mapped region is resized. Afterward, an attempt is made to
1041  * adjust the corresponding BTF info. This attempt is best-effort and can only
1042  * succeed if the last variable of the data section map is an array. The array
1043  * BTF type is replaced by a new BTF array type with a different length.
1044  * Any previously existing pointers returned from bpf_map__initial_value() or
1045  * corresponding data section skeleton pointer must be reinitialized.
1046  */
1047 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
1048 /* get map key/value BTF type IDs */
1049 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
1050 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
1051 /* get/set map if_index */
1052 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
1053 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
1054 /* get/set map map_extra flags */
1055 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
1056 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
1057 
1058 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
1059 					  const void *data, size_t size);
1060 LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize);
1061 
1062 /**
1063  * @brief **bpf_map__is_internal()** tells the caller whether or not the
1064  * passed map is a special map created by libbpf automatically for things like
1065  * global variables, __ksym externs, Kconfig values, etc
1066  * @param map the bpf_map
1067  * @return true, if the map is an internal map; false, otherwise
1068  */
1069 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
1070 
1071 /**
1072  * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
1073  * BPF map should be pinned. This does not actually create the 'pin'.
1074  * @param map The bpf_map
1075  * @param path The path
1076  * @return 0, on success; negative error, otherwise
1077  */
1078 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
1079 
1080 /**
1081  * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
1082  * BPF map should be pinned.
1083  * @param map The bpf_map
1084  * @return The path string; which can be NULL
1085  */
1086 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
1087 
1088 /**
1089  * @brief **bpf_map__is_pinned()** tells the caller whether or not the
1090  * passed map has been pinned via a 'pin' file.
1091  * @param map The bpf_map
1092  * @return true, if the map is pinned; false, otherwise
1093  */
1094 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
1095 
1096 /**
1097  * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
1098  * for the BPF map. This increments the reference count on the
1099  * BPF map which will keep the BPF map loaded even after the
1100  * userspace process which loaded it has exited.
1101  * @param map The bpf_map to pin
1102  * @param path A file path for the 'pin'
1103  * @return 0, on success; negative error, otherwise
1104  *
1105  * If `path` is NULL the maps `pin_path` attribute will be used. If this is
1106  * also NULL, an error will be returned and the map will not be pinned.
1107  */
1108 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
1109 
1110 /**
1111  * @brief **bpf_map__unpin()** removes the file that serves as a
1112  * 'pin' for the BPF map.
1113  * @param map The bpf_map to unpin
1114  * @param path A file path for the 'pin'
1115  * @return 0, on success; negative error, otherwise
1116  *
1117  * The `path` parameter can be NULL, in which case the `pin_path`
1118  * map attribute is unpinned. If both the `path` parameter and
1119  * `pin_path` map attribute are set, they must be equal.
1120  */
1121 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
1122 
1123 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
1124 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
1125 
1126 /**
1127  * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
1128  * corresponding to provided key.
1129  * @param map BPF map to lookup element in
1130  * @param key pointer to memory containing bytes of the key used for lookup
1131  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1132  * @param value pointer to memory in which looked up value will be stored
1133  * @param value_sz size in byte of value data memory; it has to match BPF map
1134  * definition's **value_size**. For per-CPU BPF maps value size has to be
1135  * a product of BPF map value size and number of possible CPUs in the system
1136  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1137  * per-CPU values value size has to be aligned up to closest 8 bytes for
1138  * alignment reasons, so expected size is: `round_up(value_size, 8)
1139  * * libbpf_num_possible_cpus()`.
1140  * @flags extra flags passed to kernel for this operation
1141  * @return 0, on success; negative error, otherwise
1142  *
1143  * **bpf_map__lookup_elem()** is high-level equivalent of
1144  * **bpf_map_lookup_elem()** API with added check for key and value size.
1145  */
1146 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1147 				    const void *key, size_t key_sz,
1148 				    void *value, size_t value_sz, __u64 flags);
1149 
1150 /**
1151  * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1152  * map that corresponds to provided key.
1153  * @param map BPF map to insert to or update element in
1154  * @param key pointer to memory containing bytes of the key
1155  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1156  * @param value pointer to memory containing bytes of the value
1157  * @param value_sz size in byte of value data memory; it has to match BPF map
1158  * definition's **value_size**. For per-CPU BPF maps value size has to be
1159  * a product of BPF map value size and number of possible CPUs in the system
1160  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1161  * per-CPU values value size has to be aligned up to closest 8 bytes for
1162  * alignment reasons, so expected size is: `round_up(value_size, 8)
1163  * * libbpf_num_possible_cpus()`.
1164  * @flags extra flags passed to kernel for this operation
1165  * @return 0, on success; negative error, otherwise
1166  *
1167  * **bpf_map__update_elem()** is high-level equivalent of
1168  * **bpf_map_update_elem()** API with added check for key and value size.
1169  */
1170 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1171 				    const void *key, size_t key_sz,
1172 				    const void *value, size_t value_sz, __u64 flags);
1173 
1174 /**
1175  * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1176  * corresponds to provided key.
1177  * @param map BPF map to delete element from
1178  * @param key pointer to memory containing bytes of the key
1179  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1180  * @flags extra flags passed to kernel for this operation
1181  * @return 0, on success; negative error, otherwise
1182  *
1183  * **bpf_map__delete_elem()** is high-level equivalent of
1184  * **bpf_map_delete_elem()** API with added check for key size.
1185  */
1186 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1187 				    const void *key, size_t key_sz, __u64 flags);
1188 
1189 /**
1190  * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1191  * corresponding to provided key and atomically delete it afterwards.
1192  * @param map BPF map to lookup element in
1193  * @param key pointer to memory containing bytes of the key used for lookup
1194  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1195  * @param value pointer to memory in which looked up value will be stored
1196  * @param value_sz size in byte of value data memory; it has to match BPF map
1197  * definition's **value_size**. For per-CPU BPF maps value size has to be
1198  * a product of BPF map value size and number of possible CPUs in the system
1199  * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1200  * per-CPU values value size has to be aligned up to closest 8 bytes for
1201  * alignment reasons, so expected size is: `round_up(value_size, 8)
1202  * * libbpf_num_possible_cpus()`.
1203  * @flags extra flags passed to kernel for this operation
1204  * @return 0, on success; negative error, otherwise
1205  *
1206  * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1207  * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1208  */
1209 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1210 					       const void *key, size_t key_sz,
1211 					       void *value, size_t value_sz, __u64 flags);
1212 
1213 /**
1214  * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1215  * fetching next key that follows current key.
1216  * @param map BPF map to fetch next key from
1217  * @param cur_key pointer to memory containing bytes of current key or NULL to
1218  * fetch the first key
1219  * @param next_key pointer to memory to write next key into
1220  * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1221  * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1222  * negative error, otherwise
1223  *
1224  * **bpf_map__get_next_key()** is high-level equivalent of
1225  * **bpf_map_get_next_key()** API with added check for key size.
1226  */
1227 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1228 				     const void *cur_key, void *next_key, size_t key_sz);
1229 
1230 struct bpf_xdp_set_link_opts {
1231 	size_t sz;
1232 	int old_fd;
1233 	size_t :0;
1234 };
1235 #define bpf_xdp_set_link_opts__last_field old_fd
1236 
1237 struct bpf_xdp_attach_opts {
1238 	size_t sz;
1239 	int old_prog_fd;
1240 	size_t :0;
1241 };
1242 #define bpf_xdp_attach_opts__last_field old_prog_fd
1243 
1244 struct bpf_xdp_query_opts {
1245 	size_t sz;
1246 	__u32 prog_id;		/* output */
1247 	__u32 drv_prog_id;	/* output */
1248 	__u32 hw_prog_id;	/* output */
1249 	__u32 skb_prog_id;	/* output */
1250 	__u8 attach_mode;	/* output */
1251 	__u64 feature_flags;	/* output */
1252 	__u32 xdp_zc_max_segs;	/* output */
1253 	size_t :0;
1254 };
1255 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1256 
1257 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1258 			      const struct bpf_xdp_attach_opts *opts);
1259 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1260 			      const struct bpf_xdp_attach_opts *opts);
1261 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1262 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1263 
1264 /* TC related API */
1265 enum bpf_tc_attach_point {
1266 	BPF_TC_INGRESS = 1 << 0,
1267 	BPF_TC_EGRESS  = 1 << 1,
1268 	BPF_TC_CUSTOM  = 1 << 2,
1269 };
1270 
1271 #define BPF_TC_PARENT(a, b) 	\
1272 	((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1273 
1274 enum bpf_tc_flags {
1275 	BPF_TC_F_REPLACE = 1 << 0,
1276 };
1277 
1278 struct bpf_tc_hook {
1279 	size_t sz;
1280 	int ifindex;
1281 	enum bpf_tc_attach_point attach_point;
1282 	__u32 parent;
1283 	size_t :0;
1284 };
1285 #define bpf_tc_hook__last_field parent
1286 
1287 struct bpf_tc_opts {
1288 	size_t sz;
1289 	int prog_fd;
1290 	__u32 flags;
1291 	__u32 prog_id;
1292 	__u32 handle;
1293 	__u32 priority;
1294 	size_t :0;
1295 };
1296 #define bpf_tc_opts__last_field priority
1297 
1298 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1299 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1300 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1301 			     struct bpf_tc_opts *opts);
1302 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1303 			     const struct bpf_tc_opts *opts);
1304 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1305 			    struct bpf_tc_opts *opts);
1306 
1307 /* Ring buffer APIs */
1308 struct ring_buffer;
1309 struct ring;
1310 struct user_ring_buffer;
1311 
1312 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1313 
1314 struct ring_buffer_opts {
1315 	size_t sz; /* size of this struct, for forward/backward compatibility */
1316 };
1317 
1318 #define ring_buffer_opts__last_field sz
1319 
1320 LIBBPF_API struct ring_buffer *
1321 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1322 		 const struct ring_buffer_opts *opts);
1323 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1324 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1325 				ring_buffer_sample_fn sample_cb, void *ctx);
1326 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1327 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1328 LIBBPF_API int ring_buffer__consume_n(struct ring_buffer *rb, size_t n);
1329 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1330 
1331 /**
1332  * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given
1333  * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance.
1334  *
1335  * @param rb A ringbuffer manager object.
1336  * @param idx An index into the ringbuffers contained within the ringbuffer
1337  * manager object. The index is 0-based and corresponds to the order in which
1338  * ring_buffer__add was called.
1339  * @return A ringbuffer object on success; NULL and errno set if the index is
1340  * invalid.
1341  */
1342 LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb,
1343 					  unsigned int idx);
1344 
1345 /**
1346  * @brief **ring__consumer_pos()** returns the current consumer position in the
1347  * given ringbuffer.
1348  *
1349  * @param r A ringbuffer object.
1350  * @return The current consumer position.
1351  */
1352 LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r);
1353 
1354 /**
1355  * @brief **ring__producer_pos()** returns the current producer position in the
1356  * given ringbuffer.
1357  *
1358  * @param r A ringbuffer object.
1359  * @return The current producer position.
1360  */
1361 LIBBPF_API unsigned long ring__producer_pos(const struct ring *r);
1362 
1363 /**
1364  * @brief **ring__avail_data_size()** returns the number of bytes in the
1365  * ringbuffer not yet consumed. This has no locking associated with it, so it
1366  * can be inaccurate if operations are ongoing while this is called. However, it
1367  * should still show the correct trend over the long-term.
1368  *
1369  * @param r A ringbuffer object.
1370  * @return The number of bytes not yet consumed.
1371  */
1372 LIBBPF_API size_t ring__avail_data_size(const struct ring *r);
1373 
1374 /**
1375  * @brief **ring__size()** returns the total size of the ringbuffer's map data
1376  * area (excluding special producer/consumer pages). Effectively this gives the
1377  * amount of usable bytes of data inside the ringbuffer.
1378  *
1379  * @param r A ringbuffer object.
1380  * @return The total size of the ringbuffer map data area.
1381  */
1382 LIBBPF_API size_t ring__size(const struct ring *r);
1383 
1384 /**
1385  * @brief **ring__map_fd()** returns the file descriptor underlying the given
1386  * ringbuffer.
1387  *
1388  * @param r A ringbuffer object.
1389  * @return The underlying ringbuffer file descriptor
1390  */
1391 LIBBPF_API int ring__map_fd(const struct ring *r);
1392 
1393 /**
1394  * @brief **ring__consume()** consumes available ringbuffer data without event
1395  * polling.
1396  *
1397  * @param r A ringbuffer object.
1398  * @return The number of records consumed (or INT_MAX, whichever is less), or
1399  * a negative number if any of the callbacks return an error.
1400  */
1401 LIBBPF_API int ring__consume(struct ring *r);
1402 
1403 /**
1404  * @brief **ring__consume_n()** consumes up to a requested amount of items from
1405  * a ringbuffer without event polling.
1406  *
1407  * @param r A ringbuffer object.
1408  * @param n Maximum amount of items to consume.
1409  * @return The number of items consumed, or a negative number if any of the
1410  * callbacks return an error.
1411  */
1412 LIBBPF_API int ring__consume_n(struct ring *r, size_t n);
1413 
1414 struct user_ring_buffer_opts {
1415 	size_t sz; /* size of this struct, for forward/backward compatibility */
1416 };
1417 
1418 #define user_ring_buffer_opts__last_field sz
1419 
1420 /**
1421  * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1422  * buffer.
1423  *
1424  * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1425  * @param opts Options for how the ring buffer should be created.
1426  * @return A user ring buffer on success; NULL and errno being set on a
1427  * failure.
1428  */
1429 LIBBPF_API struct user_ring_buffer *
1430 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1431 
1432 /**
1433  * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1434  * user ring buffer.
1435  * @param rb A pointer to a user ring buffer.
1436  * @param size The size of the sample, in bytes.
1437  * @return A pointer to an 8-byte aligned reserved region of the user ring
1438  * buffer; NULL, and errno being set if a sample could not be reserved.
1439  *
1440  * This function is *not* thread safe, and callers must synchronize accessing
1441  * this function if there are multiple producers.  If a size is requested that
1442  * is larger than the size of the entire ring buffer, errno will be set to
1443  * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1444  * but currently does not have enough space, errno is set to ENOSPC and NULL is
1445  * returned.
1446  *
1447  * After initializing the sample, callers must invoke
1448  * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1449  * the sample must be freed with **user_ring_buffer__discard()**.
1450  */
1451 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1452 
1453 /**
1454  * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1455  * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1456  * available.
1457  * @param rb The user ring buffer.
1458  * @param size The size of the sample, in bytes.
1459  * @param timeout_ms The amount of time, in milliseconds, for which the caller
1460  * should block when waiting for a sample. -1 causes the caller to block
1461  * indefinitely.
1462  * @return A pointer to an 8-byte aligned reserved region of the user ring
1463  * buffer; NULL, and errno being set if a sample could not be reserved.
1464  *
1465  * This function is *not* thread safe, and callers must synchronize
1466  * accessing this function if there are multiple producers
1467  *
1468  * If **timeout_ms** is -1, the function will block indefinitely until a sample
1469  * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1470  * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1471  * will occur and the function will return immediately after attempting to
1472  * reserve a sample.
1473  *
1474  * If **size** is larger than the size of the entire ring buffer, errno is set
1475  * to E2BIG and NULL is returned. If the ring buffer could accommodate
1476  * **size**, but currently does not have enough space, the caller will block
1477  * until at most **timeout_ms** has elapsed. If insufficient space is available
1478  * at that time, errno is set to ENOSPC, and NULL is returned.
1479  *
1480  * The kernel guarantees that it will wake up this thread to check if
1481  * sufficient space is available in the ring buffer at least once per
1482  * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1483  * least one sample is consumed, and the BPF program did not invoke the
1484  * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1485  * kernel does not guarantee this. If the helper function is invoked with
1486  * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1487  * consumed.
1488  *
1489  * When a sample of size **size** is found within **timeout_ms**, a pointer to
1490  * the sample is returned. After initializing the sample, callers must invoke
1491  * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1492  * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1493  */
1494 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1495 						    __u32 size,
1496 						    int timeout_ms);
1497 
1498 /**
1499  * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1500  * into the ring buffer.
1501  * @param rb The user ring buffer.
1502  * @param sample A reserved sample.
1503  *
1504  * It is not necessary to synchronize amongst multiple producers when invoking
1505  * this function.
1506  */
1507 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1508 
1509 /**
1510  * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1511  * @param rb The user ring buffer.
1512  * @param sample A reserved sample.
1513  *
1514  * It is not necessary to synchronize amongst multiple producers when invoking
1515  * this function.
1516  */
1517 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1518 
1519 /**
1520  * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1521  * created with **user_ring_buffer__new()**.
1522  * @param rb The user ring buffer being freed.
1523  */
1524 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1525 
1526 /* Perf buffer APIs */
1527 struct perf_buffer;
1528 
1529 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1530 				      void *data, __u32 size);
1531 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1532 
1533 /* common use perf buffer options */
1534 struct perf_buffer_opts {
1535 	size_t sz;
1536 	__u32 sample_period;
1537 	size_t :0;
1538 };
1539 #define perf_buffer_opts__last_field sample_period
1540 
1541 /**
1542  * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1543  * BPF_PERF_EVENT_ARRAY map
1544  * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1545  * code to send data over to user-space
1546  * @param page_cnt number of memory pages allocated for each per-CPU buffer
1547  * @param sample_cb function called on each received data record
1548  * @param lost_cb function called when record loss has occurred
1549  * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1550  * @return a new instance of struct perf_buffer on success, NULL on error with
1551  * *errno* containing an error code
1552  */
1553 LIBBPF_API struct perf_buffer *
1554 perf_buffer__new(int map_fd, size_t page_cnt,
1555 		 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1556 		 const struct perf_buffer_opts *opts);
1557 
1558 enum bpf_perf_event_ret {
1559 	LIBBPF_PERF_EVENT_DONE	= 0,
1560 	LIBBPF_PERF_EVENT_ERROR	= -1,
1561 	LIBBPF_PERF_EVENT_CONT	= -2,
1562 };
1563 
1564 struct perf_event_header;
1565 
1566 typedef enum bpf_perf_event_ret
1567 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1568 
1569 /* raw perf buffer options, giving most power and control */
1570 struct perf_buffer_raw_opts {
1571 	size_t sz;
1572 	long :0;
1573 	long :0;
1574 	/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1575 	 * max_entries of given PERF_EVENT_ARRAY map)
1576 	 */
1577 	int cpu_cnt;
1578 	/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1579 	int *cpus;
1580 	/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1581 	int *map_keys;
1582 };
1583 #define perf_buffer_raw_opts__last_field map_keys
1584 
1585 struct perf_event_attr;
1586 
1587 LIBBPF_API struct perf_buffer *
1588 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1589 		     perf_buffer_event_fn event_cb, void *ctx,
1590 		     const struct perf_buffer_raw_opts *opts);
1591 
1592 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1593 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1594 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1595 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1596 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1597 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1598 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1599 /**
1600  * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1601  * memory region of the ring buffer.
1602  * This ring buffer can be used to implement a custom events consumer.
1603  * The ring buffer starts with the *struct perf_event_mmap_page*, which
1604  * holds the ring buffer management fields, when accessing the header
1605  * structure it's important to be SMP aware.
1606  * You can refer to *perf_event_read_simple* for a simple example.
1607  * @param pb the perf buffer structure
1608  * @param buf_idx the buffer index to retrieve
1609  * @param buf (out) gets the base pointer of the mmap()'ed memory
1610  * @param buf_size (out) gets the size of the mmap()'ed region
1611  * @return 0 on success, negative error code for failure
1612  */
1613 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1614 				   size_t *buf_size);
1615 
1616 struct bpf_prog_linfo;
1617 struct bpf_prog_info;
1618 
1619 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1620 LIBBPF_API struct bpf_prog_linfo *
1621 bpf_prog_linfo__new(const struct bpf_prog_info *info);
1622 LIBBPF_API const struct bpf_line_info *
1623 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1624 				__u64 addr, __u32 func_idx, __u32 nr_skip);
1625 LIBBPF_API const struct bpf_line_info *
1626 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1627 		      __u32 insn_off, __u32 nr_skip);
1628 
1629 /*
1630  * Probe for supported system features
1631  *
1632  * Note that running many of these probes in a short amount of time can cause
1633  * the kernel to reach the maximal size of lockable memory allowed for the
1634  * user, causing subsequent probes to fail. In this case, the caller may want
1635  * to adjust that limit with setrlimit().
1636  */
1637 
1638 /**
1639  * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1640  * BPF programs of a given type.
1641  * @param prog_type BPF program type to detect kernel support for
1642  * @param opts reserved for future extensibility, should be NULL
1643  * @return 1, if given program type is supported; 0, if given program type is
1644  * not supported; negative error code if feature detection failed or can't be
1645  * performed
1646  *
1647  * Make sure the process has required set of CAP_* permissions (or runs as
1648  * root) when performing feature checking.
1649  */
1650 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1651 /**
1652  * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1653  * BPF maps of a given type.
1654  * @param map_type BPF map type to detect kernel support for
1655  * @param opts reserved for future extensibility, should be NULL
1656  * @return 1, if given map type is supported; 0, if given map type is
1657  * not supported; negative error code if feature detection failed or can't be
1658  * performed
1659  *
1660  * Make sure the process has required set of CAP_* permissions (or runs as
1661  * root) when performing feature checking.
1662  */
1663 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1664 /**
1665  * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1666  * use of a given BPF helper from specified BPF program type.
1667  * @param prog_type BPF program type used to check the support of BPF helper
1668  * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1669  * @param opts reserved for future extensibility, should be NULL
1670  * @return 1, if given combination of program type and helper is supported; 0,
1671  * if the combination is not supported; negative error code if feature
1672  * detection for provided input arguments failed or can't be performed
1673  *
1674  * Make sure the process has required set of CAP_* permissions (or runs as
1675  * root) when performing feature checking.
1676  */
1677 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1678 				       enum bpf_func_id helper_id, const void *opts);
1679 
1680 /**
1681  * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1682  * number of possible CPUs that the host kernel supports and expects.
1683  * @return number of possible CPUs; or error code on failure
1684  *
1685  * Example usage:
1686  *
1687  *     int ncpus = libbpf_num_possible_cpus();
1688  *     if (ncpus < 0) {
1689  *          // error handling
1690  *     }
1691  *     long values[ncpus];
1692  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1693  */
1694 LIBBPF_API int libbpf_num_possible_cpus(void);
1695 
1696 struct bpf_map_skeleton {
1697 	const char *name;
1698 	struct bpf_map **map;
1699 	void **mmaped;
1700 	struct bpf_link **link;
1701 };
1702 
1703 struct bpf_prog_skeleton {
1704 	const char *name;
1705 	struct bpf_program **prog;
1706 	struct bpf_link **link;
1707 };
1708 
1709 struct bpf_object_skeleton {
1710 	size_t sz; /* size of this struct, for forward/backward compatibility */
1711 
1712 	const char *name;
1713 	const void *data;
1714 	size_t data_sz;
1715 
1716 	struct bpf_object **obj;
1717 
1718 	int map_cnt;
1719 	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1720 	struct bpf_map_skeleton *maps;
1721 
1722 	int prog_cnt;
1723 	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1724 	struct bpf_prog_skeleton *progs;
1725 };
1726 
1727 LIBBPF_API int
1728 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1729 			  const struct bpf_object_open_opts *opts);
1730 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1731 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1732 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1733 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1734 
1735 struct bpf_var_skeleton {
1736 	const char *name;
1737 	struct bpf_map **map;
1738 	void **addr;
1739 };
1740 
1741 struct bpf_object_subskeleton {
1742 	size_t sz; /* size of this struct, for forward/backward compatibility */
1743 
1744 	const struct bpf_object *obj;
1745 
1746 	int map_cnt;
1747 	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1748 	struct bpf_map_skeleton *maps;
1749 
1750 	int prog_cnt;
1751 	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1752 	struct bpf_prog_skeleton *progs;
1753 
1754 	int var_cnt;
1755 	int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1756 	struct bpf_var_skeleton *vars;
1757 };
1758 
1759 LIBBPF_API int
1760 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1761 LIBBPF_API void
1762 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1763 
1764 struct gen_loader_opts {
1765 	size_t sz; /* size of this struct, for forward/backward compatibility */
1766 	const char *data;
1767 	const char *insns;
1768 	__u32 data_sz;
1769 	__u32 insns_sz;
1770 };
1771 
1772 #define gen_loader_opts__last_field insns_sz
1773 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1774 				      struct gen_loader_opts *opts);
1775 
1776 enum libbpf_tristate {
1777 	TRI_NO = 0,
1778 	TRI_YES = 1,
1779 	TRI_MODULE = 2,
1780 };
1781 
1782 struct bpf_linker_opts {
1783 	/* size of this struct, for forward/backward compatibility */
1784 	size_t sz;
1785 };
1786 #define bpf_linker_opts__last_field sz
1787 
1788 struct bpf_linker_file_opts {
1789 	/* size of this struct, for forward/backward compatibility */
1790 	size_t sz;
1791 };
1792 #define bpf_linker_file_opts__last_field sz
1793 
1794 struct bpf_linker;
1795 
1796 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1797 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1798 				    const char *filename,
1799 				    const struct bpf_linker_file_opts *opts);
1800 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1801 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1802 
1803 /*
1804  * Custom handling of BPF program's SEC() definitions
1805  */
1806 
1807 struct bpf_prog_load_opts; /* defined in bpf.h */
1808 
1809 /* Called during bpf_object__open() for each recognized BPF program. Callback
1810  * can use various bpf_program__set_*() setters to adjust whatever properties
1811  * are necessary.
1812  */
1813 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1814 
1815 /* Called right before libbpf performs bpf_prog_load() to load BPF program
1816  * into the kernel. Callback can adjust opts as necessary.
1817  */
1818 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1819 					     struct bpf_prog_load_opts *opts, long cookie);
1820 
1821 /* Called during skeleton attach or through bpf_program__attach(). If
1822  * auto-attach is not supported, callback should return 0 and set link to
1823  * NULL (it's not considered an error during skeleton attach, but it will be
1824  * an error for bpf_program__attach() calls). On error, error should be
1825  * returned directly and link set to NULL. On success, return 0 and set link
1826  * to a valid struct bpf_link.
1827  */
1828 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1829 				       struct bpf_link **link);
1830 
1831 struct libbpf_prog_handler_opts {
1832 	/* size of this struct, for forward/backward compatibility */
1833 	size_t sz;
1834 	/* User-provided value that is passed to prog_setup_fn,
1835 	 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1836 	 * register one set of callbacks for multiple SEC() definitions and
1837 	 * still be able to distinguish them, if necessary. For example,
1838 	 * libbpf itself is using this to pass necessary flags (e.g.,
1839 	 * sleepable flag) to a common internal SEC() handler.
1840 	 */
1841 	long cookie;
1842 	/* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1843 	 * Callback is optional, pass NULL if it's not necessary.
1844 	 */
1845 	libbpf_prog_setup_fn_t prog_setup_fn;
1846 	/* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1847 	 * Callback is optional, pass NULL if it's not necessary.
1848 	 */
1849 	libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1850 	/* BPF program attach callback (see libbpf_prog_attach_fn_t).
1851 	 * Callback is optional, pass NULL if it's not necessary.
1852 	 */
1853 	libbpf_prog_attach_fn_t prog_attach_fn;
1854 };
1855 #define libbpf_prog_handler_opts__last_field prog_attach_fn
1856 
1857 /**
1858  * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1859  * SEC() handler.
1860  * @param sec section prefix for which custom handler is registered
1861  * @param prog_type BPF program type associated with specified section
1862  * @param exp_attach_type Expected BPF attach type associated with specified section
1863  * @param opts optional cookie, callbacks, and other extra options
1864  * @return Non-negative handler ID is returned on success. This handler ID has
1865  * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1866  * custom handler. Negative error code is returned on error.
1867  *
1868  * *sec* defines which SEC() definitions are handled by this custom handler
1869  * registration. *sec* can have few different forms:
1870  *   - if *sec* is just a plain string (e.g., "abc"), it will match only
1871  *   SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1872  *   in an error;
1873  *   - if *sec* is of the form "abc/", proper SEC() form is
1874  *   SEC("abc/something"), where acceptable "something" should be checked by
1875  *   *prog_init_fn* callback, if there are additional restrictions;
1876  *   - if *sec* is of the form "abc+", it will successfully match both
1877  *   SEC("abc") and SEC("abc/whatever") forms;
1878  *   - if *sec* is NULL, custom handler is registered for any BPF program that
1879  *   doesn't match any of the registered (custom or libbpf's own) SEC()
1880  *   handlers. There could be only one such generic custom handler registered
1881  *   at any given time.
1882  *
1883  * All custom handlers (except the one with *sec* == NULL) are processed
1884  * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1885  * SEC() handlers by registering custom ones for the same section prefix
1886  * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1887  * handler).
1888  *
1889  * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1890  * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1891  * to ensure synchronization if there is a risk of running this API from
1892  * multiple threads simultaneously.
1893  */
1894 LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1895 					    enum bpf_prog_type prog_type,
1896 					    enum bpf_attach_type exp_attach_type,
1897 					    const struct libbpf_prog_handler_opts *opts);
1898 /**
1899  * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1900  * custom BPF program SEC() handler.
1901  * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1902  * after successful registration
1903  * @return 0 on success, negative error code if handler isn't found
1904  *
1905  * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1906  * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1907  * to ensure synchronization if there is a risk of running this API from
1908  * multiple threads simultaneously.
1909  */
1910 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1911 
1912 #ifdef __cplusplus
1913 } /* extern "C" */
1914 #endif
1915 
1916 #endif /* __LIBBPF_LIBBPF_H */
1917