xref: /openbmc/linux/tools/lib/bpf/libbpf.h (revision e330fb14)
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 enum libbpf_errno {
28 	__LIBBPF_ERRNO__START = 4000,
29 
30 	/* Something wrong in libelf */
31 	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
32 	LIBBPF_ERRNO__FORMAT,	/* BPF object format invalid */
33 	LIBBPF_ERRNO__KVERSION,	/* Incorrect or no 'version' section */
34 	LIBBPF_ERRNO__ENDIAN,	/* Endian mismatch */
35 	LIBBPF_ERRNO__INTERNAL,	/* Internal error in libbpf */
36 	LIBBPF_ERRNO__RELOC,	/* Relocation failed */
37 	LIBBPF_ERRNO__LOAD,	/* Load program failure for unknown reason */
38 	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
39 	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
40 	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
41 	LIBBPF_ERRNO__PROGTYPE,	/* Kernel doesn't support this program type */
42 	LIBBPF_ERRNO__WRNGPID,	/* Wrong pid in netlink message */
43 	LIBBPF_ERRNO__INVSEQ,	/* Invalid netlink sequence */
44 	LIBBPF_ERRNO__NLPARSE,	/* netlink parsing error */
45 	__LIBBPF_ERRNO__END,
46 };
47 
48 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
49 
50 enum libbpf_print_level {
51         LIBBPF_WARN,
52         LIBBPF_INFO,
53         LIBBPF_DEBUG,
54 };
55 
56 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
57 				 const char *, va_list ap);
58 
59 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
60 
61 /* Hide internal to user */
62 struct bpf_object;
63 
64 struct bpf_object_open_attr {
65 	const char *file;
66 	enum bpf_prog_type prog_type;
67 };
68 
69 struct bpf_object_open_opts {
70 	/* size of this struct, for forward/backward compatiblity */
71 	size_t sz;
72 	/* object name override, if provided:
73 	 * - for object open from file, this will override setting object
74 	 *   name from file path's base name;
75 	 * - for object open from memory buffer, this will specify an object
76 	 *   name and will override default "<addr>-<buf-size>" name;
77 	 */
78 	const char *object_name;
79 	/* parse map definitions non-strictly, allowing extra attributes/data */
80 	bool relaxed_maps;
81 	/* DEPRECATED: handle CO-RE relocations non-strictly, allowing failures.
82 	 * Value is ignored. Relocations always are processed non-strictly.
83 	 * Non-relocatable instructions are replaced with invalid ones to
84 	 * prevent accidental errors.
85 	 * */
86 	LIBBPF_DEPRECATED_SINCE(0, 6, "field has no effect")
87 	bool relaxed_core_relocs;
88 	/* maps that set the 'pinning' attribute in their definition will have
89 	 * their pin_path attribute set to a file in this directory, and be
90 	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
91 	 */
92 	const char *pin_root_path;
93 
94 	LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__set_attach_target() on each individual bpf_program")
95 	__u32 attach_prog_fd;
96 	/* Additional kernel config content that augments and overrides
97 	 * system Kconfig for CONFIG_xxx externs.
98 	 */
99 	const char *kconfig;
100 	/* Path to the custom BTF to be used for BPF CO-RE relocations.
101 	 * This custom BTF completely replaces the use of vmlinux BTF
102 	 * for the purpose of CO-RE relocations.
103 	 * NOTE: any other BPF feature (e.g., fentry/fexit programs,
104 	 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
105 	 */
106 	const char *btf_custom_path;
107 };
108 #define bpf_object_open_opts__last_field btf_custom_path
109 
110 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
111 LIBBPF_API struct bpf_object *
112 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
113 LIBBPF_API struct bpf_object *
114 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
115 		     const struct bpf_object_open_opts *opts);
116 
117 /* deprecated bpf_object__open variants */
118 LIBBPF_API struct bpf_object *
119 bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
120 			const char *name);
121 LIBBPF_API struct bpf_object *
122 bpf_object__open_xattr(struct bpf_object_open_attr *attr);
123 
124 enum libbpf_pin_type {
125 	LIBBPF_PIN_NONE,
126 	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
127 	LIBBPF_PIN_BY_NAME,
128 };
129 
130 /* pin_maps and unpin_maps can both be called with a NULL path, in which case
131  * they will use the pin_path attribute of each map (and ignore all maps that
132  * don't have a pin_path set).
133  */
134 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
135 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
136 				      const char *path);
137 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
138 					const char *path);
139 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
140 					  const char *path);
141 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
142 LIBBPF_API void bpf_object__close(struct bpf_object *object);
143 
144 struct bpf_object_load_attr {
145 	struct bpf_object *obj;
146 	int log_level;
147 	const char *target_btf_path;
148 };
149 
150 /* Load/unload object into/from kernel */
151 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
152 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
153 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
154 
155 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
156 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
157 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
158 
159 struct btf;
160 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
161 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
162 
163 LIBBPF_API struct bpf_program *
164 bpf_object__find_program_by_title(const struct bpf_object *obj,
165 				  const char *title);
166 LIBBPF_API struct bpf_program *
167 bpf_object__find_program_by_name(const struct bpf_object *obj,
168 				 const char *name);
169 
170 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
171 #define bpf_object__for_each_safe(pos, tmp)			\
172 	for ((pos) = bpf_object__next(NULL),		\
173 		(tmp) = bpf_object__next(pos);		\
174 	     (pos) != NULL;				\
175 	     (pos) = (tmp), (tmp) = bpf_object__next(tmp))
176 
177 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
178 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
179 				    bpf_object_clear_priv_t clear_priv);
180 LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);
181 
182 LIBBPF_API int
183 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
184 			 enum bpf_attach_type *expected_attach_type);
185 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
186 					  enum bpf_attach_type *attach_type);
187 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
188 					  enum bpf_attach_type attach_type);
189 
190 /* Accessors of bpf_program */
191 struct bpf_program;
192 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
193 						 const struct bpf_object *obj);
194 
195 #define bpf_object__for_each_program(pos, obj)		\
196 	for ((pos) = bpf_program__next(NULL, (obj));	\
197 	     (pos) != NULL;				\
198 	     (pos) = bpf_program__next((pos), (obj)))
199 
200 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
201 						 const struct bpf_object *obj);
202 
203 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
204 
205 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
206 				     bpf_program_clear_priv_t clear_priv);
207 
208 LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
209 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
210 					 __u32 ifindex);
211 
212 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
213 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
214 LIBBPF_API LIBBPF_DEPRECATED("BPF program title is confusing term; please use bpf_program__section_name() instead")
215 const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy);
216 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
217 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
218 
219 /* returns program size in bytes */
220 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
221 
222 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
223 				 __u32 kern_version);
224 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
225 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
226 					 const char *path,
227 					 int instance);
228 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
229 					   const char *path,
230 					   int instance);
231 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
232 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
233 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
234 
235 struct bpf_link;
236 
237 LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
238 LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
239 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
240 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
241 LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
242 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
243 					struct bpf_program *prog);
244 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
245 LIBBPF_API int bpf_link__detach(struct bpf_link *link);
246 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
247 
248 LIBBPF_API struct bpf_link *
249 bpf_program__attach(const struct bpf_program *prog);
250 
251 struct bpf_perf_event_opts {
252 	/* size of this struct, for forward/backward compatiblity */
253 	size_t sz;
254 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
255 	__u64 bpf_cookie;
256 };
257 #define bpf_perf_event_opts__last_field bpf_cookie
258 
259 LIBBPF_API struct bpf_link *
260 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
261 
262 LIBBPF_API struct bpf_link *
263 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
264 				    const struct bpf_perf_event_opts *opts);
265 
266 struct bpf_kprobe_opts {
267 	/* size of this struct, for forward/backward compatiblity */
268 	size_t sz;
269 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
270 	__u64 bpf_cookie;
271 	/* function's offset to install kprobe to */
272 	size_t offset;
273 	/* kprobe is return probe */
274 	bool retprobe;
275 	size_t :0;
276 };
277 #define bpf_kprobe_opts__last_field retprobe
278 
279 LIBBPF_API struct bpf_link *
280 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
281 			   const char *func_name);
282 LIBBPF_API struct bpf_link *
283 bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
284                                 const char *func_name,
285                                 const struct bpf_kprobe_opts *opts);
286 
287 struct bpf_uprobe_opts {
288 	/* size of this struct, for forward/backward compatiblity */
289 	size_t sz;
290 	/* offset of kernel reference counted USDT semaphore, added in
291 	 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
292 	 */
293 	size_t ref_ctr_offset;
294 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
295 	__u64 bpf_cookie;
296 	/* uprobe is return probe, invoked at function return time */
297 	bool retprobe;
298 	size_t :0;
299 };
300 #define bpf_uprobe_opts__last_field retprobe
301 
302 LIBBPF_API struct bpf_link *
303 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
304 			   pid_t pid, const char *binary_path,
305 			   size_t func_offset);
306 LIBBPF_API struct bpf_link *
307 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
308 				const char *binary_path, size_t func_offset,
309 				const struct bpf_uprobe_opts *opts);
310 
311 struct bpf_tracepoint_opts {
312 	/* size of this struct, for forward/backward compatiblity */
313 	size_t sz;
314 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
315 	__u64 bpf_cookie;
316 };
317 #define bpf_tracepoint_opts__last_field bpf_cookie
318 
319 LIBBPF_API struct bpf_link *
320 bpf_program__attach_tracepoint(const struct bpf_program *prog,
321 			       const char *tp_category,
322 			       const char *tp_name);
323 LIBBPF_API struct bpf_link *
324 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
325 				    const char *tp_category,
326 				    const char *tp_name,
327 				    const struct bpf_tracepoint_opts *opts);
328 
329 LIBBPF_API struct bpf_link *
330 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
331 				   const char *tp_name);
332 LIBBPF_API struct bpf_link *
333 bpf_program__attach_trace(const struct bpf_program *prog);
334 LIBBPF_API struct bpf_link *
335 bpf_program__attach_lsm(const struct bpf_program *prog);
336 LIBBPF_API struct bpf_link *
337 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
338 LIBBPF_API struct bpf_link *
339 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
340 LIBBPF_API struct bpf_link *
341 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
342 LIBBPF_API struct bpf_link *
343 bpf_program__attach_freplace(const struct bpf_program *prog,
344 			     int target_fd, const char *attach_func_name);
345 
346 struct bpf_map;
347 
348 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
349 
350 struct bpf_iter_attach_opts {
351 	size_t sz; /* size of this struct for forward/backward compatibility */
352 	union bpf_iter_link_info *link_info;
353 	__u32 link_info_len;
354 };
355 #define bpf_iter_attach_opts__last_field link_info_len
356 
357 LIBBPF_API struct bpf_link *
358 bpf_program__attach_iter(const struct bpf_program *prog,
359 			 const struct bpf_iter_attach_opts *opts);
360 
361 struct bpf_insn;
362 
363 /*
364  * Libbpf allows callers to adjust BPF programs before being loaded
365  * into kernel. One program in an object file can be transformed into
366  * multiple variants to be attached to different hooks.
367  *
368  * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
369  * form an API for this purpose.
370  *
371  * - bpf_program_prep_t:
372  *   Defines a 'preprocessor', which is a caller defined function
373  *   passed to libbpf through bpf_program__set_prep(), and will be
374  *   called before program is loaded. The processor should adjust
375  *   the program one time for each instance according to the instance id
376  *   passed to it.
377  *
378  * - bpf_program__set_prep:
379  *   Attaches a preprocessor to a BPF program. The number of instances
380  *   that should be created is also passed through this function.
381  *
382  * - bpf_program__nth_fd:
383  *   After the program is loaded, get resulting FD of a given instance
384  *   of the BPF program.
385  *
386  * If bpf_program__set_prep() is not used, the program would be loaded
387  * without adjustment during bpf_object__load(). The program has only
388  * one instance. In this case bpf_program__fd(prog) is equal to
389  * bpf_program__nth_fd(prog, 0).
390  */
391 
392 struct bpf_prog_prep_result {
393 	/*
394 	 * If not NULL, load new instruction array.
395 	 * If set to NULL, don't load this instance.
396 	 */
397 	struct bpf_insn *new_insn_ptr;
398 	int new_insn_cnt;
399 
400 	/* If not NULL, result FD is written to it. */
401 	int *pfd;
402 };
403 
404 /*
405  * Parameters of bpf_program_prep_t:
406  *  - prog:	The bpf_program being loaded.
407  *  - n:	Index of instance being generated.
408  *  - insns:	BPF instructions array.
409  *  - insns_cnt:Number of instructions in insns.
410  *  - res:	Output parameter, result of transformation.
411  *
412  * Return value:
413  *  - Zero:	pre-processing success.
414  *  - Non-zero:	pre-processing error, stop loading.
415  */
416 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
417 				  struct bpf_insn *insns, int insns_cnt,
418 				  struct bpf_prog_prep_result *res);
419 
420 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
421 				     bpf_program_prep_t prep);
422 
423 LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
424 
425 /*
426  * Adjust type of BPF program. Default is kprobe.
427  */
428 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
429 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
430 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
431 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
432 LIBBPF_API int bpf_program__set_lsm(struct bpf_program *prog);
433 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
434 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
435 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
436 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
437 LIBBPF_API int bpf_program__set_tracing(struct bpf_program *prog);
438 LIBBPF_API int bpf_program__set_struct_ops(struct bpf_program *prog);
439 LIBBPF_API int bpf_program__set_extension(struct bpf_program *prog);
440 LIBBPF_API int bpf_program__set_sk_lookup(struct bpf_program *prog);
441 
442 LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
443 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
444 				      enum bpf_prog_type type);
445 
446 LIBBPF_API enum bpf_attach_type
447 bpf_program__get_expected_attach_type(const struct bpf_program *prog);
448 LIBBPF_API void
449 bpf_program__set_expected_attach_type(struct bpf_program *prog,
450 				      enum bpf_attach_type type);
451 
452 LIBBPF_API int
453 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
454 			       const char *attach_func_name);
455 
456 LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
457 LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
458 LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
459 LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
460 LIBBPF_API bool bpf_program__is_lsm(const struct bpf_program *prog);
461 LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
462 LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
463 LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
464 LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
465 LIBBPF_API bool bpf_program__is_tracing(const struct bpf_program *prog);
466 LIBBPF_API bool bpf_program__is_struct_ops(const struct bpf_program *prog);
467 LIBBPF_API bool bpf_program__is_extension(const struct bpf_program *prog);
468 LIBBPF_API bool bpf_program__is_sk_lookup(const struct bpf_program *prog);
469 
470 /*
471  * No need for __attribute__((packed)), all members of 'bpf_map_def'
472  * are all aligned.  In addition, using __attribute__((packed))
473  * would trigger a -Wpacked warning message, and lead to an error
474  * if -Werror is set.
475  */
476 struct bpf_map_def {
477 	unsigned int type;
478 	unsigned int key_size;
479 	unsigned int value_size;
480 	unsigned int max_entries;
481 	unsigned int map_flags;
482 };
483 
484 /**
485  * @brief **bpf_object__find_map_by_name()** returns BPF map of
486  * the given name, if it exists within the passed BPF object
487  * @param obj BPF object
488  * @param name name of the BPF map
489  * @return BPF map instance, if such map exists within the BPF object;
490  * or NULL otherwise.
491  */
492 LIBBPF_API struct bpf_map *
493 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
494 
495 LIBBPF_API int
496 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
497 
498 /*
499  * Get bpf_map through the offset of corresponding struct bpf_map_def
500  * in the BPF object file.
501  */
502 LIBBPF_API struct bpf_map *
503 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
504 
505 LIBBPF_API struct bpf_map *
506 bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
507 #define bpf_object__for_each_map(pos, obj)		\
508 	for ((pos) = bpf_map__next(NULL, (obj));	\
509 	     (pos) != NULL;				\
510 	     (pos) = bpf_map__next((pos), (obj)))
511 #define bpf_map__for_each bpf_object__for_each_map
512 
513 LIBBPF_API struct bpf_map *
514 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
515 
516 /**
517  * @brief **bpf_map__fd()** gets the file descriptor of the passed
518  * BPF map
519  * @param map the BPF map instance
520  * @return the file descriptor; or -EINVAL in case of an error
521  */
522 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
523 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
524 /* get map definition */
525 LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
526 /* get map name */
527 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
528 /* get/set map type */
529 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
530 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
531 /* get/set map size (max_entries) */
532 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
533 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
534 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
535 /* get/set map flags */
536 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
537 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
538 /* get/set map NUMA node */
539 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
540 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
541 /* get/set map key size */
542 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
543 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
544 /* get/set map value size */
545 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
546 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
547 /* get map key/value BTF type IDs */
548 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
549 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
550 /* get/set map if_index */
551 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
552 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
553 
554 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
555 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
556 				 bpf_map_clear_priv_t clear_priv);
557 LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
558 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
559 					  const void *data, size_t size);
560 LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
561 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
562 
563 /**
564  * @brief **bpf_map__is_internal()** tells the caller whether or not the
565  * passed map is a special map created by libbpf automatically for things like
566  * global variables, __ksym externs, Kconfig values, etc
567  * @param map the bpf_map
568  * @return true, if the map is an internal map; false, otherwise
569  */
570 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
571 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
572 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
573 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
574 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
575 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
576 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
577 
578 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
579 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
580 
581 /**
582  * @brief **libbpf_get_error()** extracts the error code from the passed
583  * pointer
584  * @param ptr pointer returned from libbpf API function
585  * @return error code; or 0 if no error occured
586  *
587  * Many libbpf API functions which return pointers have logic to encode error
588  * codes as pointers, and do not return NULL. Meaning **libbpf_get_error()**
589  * should be used on the return value from these functions immediately after
590  * calling the API function, with no intervening calls that could clobber the
591  * `errno` variable. Consult the individual functions documentation to verify
592  * if this logic applies should be used.
593  *
594  * For these API functions, if `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)`
595  * is enabled, NULL is returned on error instead.
596  *
597  * If ptr is NULL, then errno should be already set by the failing
598  * API, because libbpf never returns NULL on success and it now always
599  * sets errno on error.
600  *
601  * Example usage:
602  *
603  *   struct perf_buffer *pb;
604  *
605  *   pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES, &opts);
606  *   err = libbpf_get_error(pb);
607  *   if (err) {
608  *	  pb = NULL;
609  *	  fprintf(stderr, "failed to open perf buffer: %d\n", err);
610  *	  goto cleanup;
611  *   }
612  */
613 LIBBPF_API long libbpf_get_error(const void *ptr);
614 
615 struct bpf_prog_load_attr {
616 	const char *file;
617 	enum bpf_prog_type prog_type;
618 	enum bpf_attach_type expected_attach_type;
619 	int ifindex;
620 	int log_level;
621 	int prog_flags;
622 };
623 
624 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
625 				   struct bpf_object **pobj, int *prog_fd);
626 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
627 			     struct bpf_object **pobj, int *prog_fd);
628 
629 /* XDP related API */
630 struct xdp_link_info {
631 	__u32 prog_id;
632 	__u32 drv_prog_id;
633 	__u32 hw_prog_id;
634 	__u32 skb_prog_id;
635 	__u8 attach_mode;
636 };
637 
638 struct bpf_xdp_set_link_opts {
639 	size_t sz;
640 	int old_fd;
641 	size_t :0;
642 };
643 #define bpf_xdp_set_link_opts__last_field old_fd
644 
645 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
646 LIBBPF_API int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags,
647 					const struct bpf_xdp_set_link_opts *opts);
648 LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
649 LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
650 				     size_t info_size, __u32 flags);
651 
652 /* TC related API */
653 enum bpf_tc_attach_point {
654 	BPF_TC_INGRESS = 1 << 0,
655 	BPF_TC_EGRESS  = 1 << 1,
656 	BPF_TC_CUSTOM  = 1 << 2,
657 };
658 
659 #define BPF_TC_PARENT(a, b) 	\
660 	((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
661 
662 enum bpf_tc_flags {
663 	BPF_TC_F_REPLACE = 1 << 0,
664 };
665 
666 struct bpf_tc_hook {
667 	size_t sz;
668 	int ifindex;
669 	enum bpf_tc_attach_point attach_point;
670 	__u32 parent;
671 	size_t :0;
672 };
673 #define bpf_tc_hook__last_field parent
674 
675 struct bpf_tc_opts {
676 	size_t sz;
677 	int prog_fd;
678 	__u32 flags;
679 	__u32 prog_id;
680 	__u32 handle;
681 	__u32 priority;
682 	size_t :0;
683 };
684 #define bpf_tc_opts__last_field priority
685 
686 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
687 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
688 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
689 			     struct bpf_tc_opts *opts);
690 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
691 			     const struct bpf_tc_opts *opts);
692 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
693 			    struct bpf_tc_opts *opts);
694 
695 /* Ring buffer APIs */
696 struct ring_buffer;
697 
698 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
699 
700 struct ring_buffer_opts {
701 	size_t sz; /* size of this struct, for forward/backward compatiblity */
702 };
703 
704 #define ring_buffer_opts__last_field sz
705 
706 LIBBPF_API struct ring_buffer *
707 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
708 		 const struct ring_buffer_opts *opts);
709 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
710 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
711 				ring_buffer_sample_fn sample_cb, void *ctx);
712 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
713 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
714 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
715 
716 /* Perf buffer APIs */
717 struct perf_buffer;
718 
719 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
720 				      void *data, __u32 size);
721 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
722 
723 /* common use perf buffer options */
724 struct perf_buffer_opts {
725 	/* if specified, sample_cb is called for each sample */
726 	perf_buffer_sample_fn sample_cb;
727 	/* if specified, lost_cb is called for each batch of lost samples */
728 	perf_buffer_lost_fn lost_cb;
729 	/* ctx is provided to sample_cb and lost_cb */
730 	void *ctx;
731 };
732 
733 LIBBPF_API struct perf_buffer *
734 perf_buffer__new(int map_fd, size_t page_cnt,
735 		 const struct perf_buffer_opts *opts);
736 
737 enum bpf_perf_event_ret {
738 	LIBBPF_PERF_EVENT_DONE	= 0,
739 	LIBBPF_PERF_EVENT_ERROR	= -1,
740 	LIBBPF_PERF_EVENT_CONT	= -2,
741 };
742 
743 struct perf_event_header;
744 
745 typedef enum bpf_perf_event_ret
746 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
747 
748 /* raw perf buffer options, giving most power and control */
749 struct perf_buffer_raw_opts {
750 	/* perf event attrs passed directly into perf_event_open() */
751 	struct perf_event_attr *attr;
752 	/* raw event callback */
753 	perf_buffer_event_fn event_cb;
754 	/* ctx is provided to event_cb */
755 	void *ctx;
756 	/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
757 	 * max_entries of given PERF_EVENT_ARRAY map)
758 	 */
759 	int cpu_cnt;
760 	/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
761 	int *cpus;
762 	/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
763 	int *map_keys;
764 };
765 
766 LIBBPF_API struct perf_buffer *
767 perf_buffer__new_raw(int map_fd, size_t page_cnt,
768 		     const struct perf_buffer_raw_opts *opts);
769 
770 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
771 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
772 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
773 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
774 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
775 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
776 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
777 
778 typedef enum bpf_perf_event_ret
779 	(*bpf_perf_event_print_t)(struct perf_event_header *hdr,
780 				  void *private_data);
781 LIBBPF_API enum bpf_perf_event_ret
782 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
783 			   void **copy_mem, size_t *copy_size,
784 			   bpf_perf_event_print_t fn, void *private_data);
785 
786 struct bpf_prog_linfo;
787 struct bpf_prog_info;
788 
789 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
790 LIBBPF_API struct bpf_prog_linfo *
791 bpf_prog_linfo__new(const struct bpf_prog_info *info);
792 LIBBPF_API const struct bpf_line_info *
793 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
794 				__u64 addr, __u32 func_idx, __u32 nr_skip);
795 LIBBPF_API const struct bpf_line_info *
796 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
797 		      __u32 insn_off, __u32 nr_skip);
798 
799 /*
800  * Probe for supported system features
801  *
802  * Note that running many of these probes in a short amount of time can cause
803  * the kernel to reach the maximal size of lockable memory allowed for the
804  * user, causing subsequent probes to fail. In this case, the caller may want
805  * to adjust that limit with setrlimit().
806  */
807 LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
808 				    __u32 ifindex);
809 LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
810 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
811 				 enum bpf_prog_type prog_type, __u32 ifindex);
812 LIBBPF_API bool bpf_probe_large_insn_limit(__u32 ifindex);
813 
814 /*
815  * Get bpf_prog_info in continuous memory
816  *
817  * struct bpf_prog_info has multiple arrays. The user has option to choose
818  * arrays to fetch from kernel. The following APIs provide an uniform way to
819  * fetch these data. All arrays in bpf_prog_info are stored in a single
820  * continuous memory region. This makes it easy to store the info in a
821  * file.
822  *
823  * Before writing bpf_prog_info_linear to files, it is necessary to
824  * translate pointers in bpf_prog_info to offsets. Helper functions
825  * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
826  * are introduced to switch between pointers and offsets.
827  *
828  * Examples:
829  *   # To fetch map_ids and prog_tags:
830  *   __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
831  *           (1UL << BPF_PROG_INFO_PROG_TAGS);
832  *   struct bpf_prog_info_linear *info_linear =
833  *           bpf_program__get_prog_info_linear(fd, arrays);
834  *
835  *   # To save data in file
836  *   bpf_program__bpil_addr_to_offs(info_linear);
837  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
838  *
839  *   # To read data from file
840  *   read(f, info_linear, <proper_size>);
841  *   bpf_program__bpil_offs_to_addr(info_linear);
842  */
843 enum bpf_prog_info_array {
844 	BPF_PROG_INFO_FIRST_ARRAY = 0,
845 	BPF_PROG_INFO_JITED_INSNS = 0,
846 	BPF_PROG_INFO_XLATED_INSNS,
847 	BPF_PROG_INFO_MAP_IDS,
848 	BPF_PROG_INFO_JITED_KSYMS,
849 	BPF_PROG_INFO_JITED_FUNC_LENS,
850 	BPF_PROG_INFO_FUNC_INFO,
851 	BPF_PROG_INFO_LINE_INFO,
852 	BPF_PROG_INFO_JITED_LINE_INFO,
853 	BPF_PROG_INFO_PROG_TAGS,
854 	BPF_PROG_INFO_LAST_ARRAY,
855 };
856 
857 struct bpf_prog_info_linear {
858 	/* size of struct bpf_prog_info, when the tool is compiled */
859 	__u32			info_len;
860 	/* total bytes allocated for data, round up to 8 bytes */
861 	__u32			data_len;
862 	/* which arrays are included in data */
863 	__u64			arrays;
864 	struct bpf_prog_info	info;
865 	__u8			data[];
866 };
867 
868 LIBBPF_API struct bpf_prog_info_linear *
869 bpf_program__get_prog_info_linear(int fd, __u64 arrays);
870 
871 LIBBPF_API void
872 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
873 
874 LIBBPF_API void
875 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
876 
877 /**
878  * @brief **libbpf_num_possible_cpus()** is a helper function to get the
879  * number of possible CPUs that the host kernel supports and expects.
880  * @return number of possible CPUs; or error code on failure
881  *
882  * Example usage:
883  *
884  *     int ncpus = libbpf_num_possible_cpus();
885  *     if (ncpus < 0) {
886  *          // error handling
887  *     }
888  *     long values[ncpus];
889  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
890  */
891 LIBBPF_API int libbpf_num_possible_cpus(void);
892 
893 struct bpf_map_skeleton {
894 	const char *name;
895 	struct bpf_map **map;
896 	void **mmaped;
897 };
898 
899 struct bpf_prog_skeleton {
900 	const char *name;
901 	struct bpf_program **prog;
902 	struct bpf_link **link;
903 };
904 
905 struct bpf_object_skeleton {
906 	size_t sz; /* size of this struct, for forward/backward compatibility */
907 
908 	const char *name;
909 	const void *data;
910 	size_t data_sz;
911 
912 	struct bpf_object **obj;
913 
914 	int map_cnt;
915 	int map_skel_sz; /* sizeof(struct bpf_skeleton_map) */
916 	struct bpf_map_skeleton *maps;
917 
918 	int prog_cnt;
919 	int prog_skel_sz; /* sizeof(struct bpf_skeleton_prog) */
920 	struct bpf_prog_skeleton *progs;
921 };
922 
923 LIBBPF_API int
924 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
925 			  const struct bpf_object_open_opts *opts);
926 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
927 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
928 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
929 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
930 
931 struct gen_loader_opts {
932 	size_t sz; /* size of this struct, for forward/backward compatiblity */
933 	const char *data;
934 	const char *insns;
935 	__u32 data_sz;
936 	__u32 insns_sz;
937 };
938 
939 #define gen_loader_opts__last_field insns_sz
940 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
941 				      struct gen_loader_opts *opts);
942 
943 enum libbpf_tristate {
944 	TRI_NO = 0,
945 	TRI_YES = 1,
946 	TRI_MODULE = 2,
947 };
948 
949 struct bpf_linker_opts {
950 	/* size of this struct, for forward/backward compatiblity */
951 	size_t sz;
952 };
953 #define bpf_linker_opts__last_field sz
954 
955 struct bpf_linker_file_opts {
956 	/* size of this struct, for forward/backward compatiblity */
957 	size_t sz;
958 };
959 #define bpf_linker_file_opts__last_field sz
960 
961 struct bpf_linker;
962 
963 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
964 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
965 				    const char *filename,
966 				    const struct bpf_linker_file_opts *opts);
967 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
968 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
969 
970 #ifdef __cplusplus
971 } /* extern "C" */
972 #endif
973 
974 #endif /* __LIBBPF_LIBBPF_H */
975