xref: /openbmc/linux/tools/lib/bpf/libbpf.h (revision 1a18374f)
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 #ifdef __cplusplus
21 extern "C" {
22 #endif
23 
24 #ifndef LIBBPF_API
25 #define LIBBPF_API __attribute__((visibility("default")))
26 #endif
27 
28 enum libbpf_errno {
29 	__LIBBPF_ERRNO__START = 4000,
30 
31 	/* Something wrong in libelf */
32 	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
33 	LIBBPF_ERRNO__FORMAT,	/* BPF object format invalid */
34 	LIBBPF_ERRNO__KVERSION,	/* Incorrect or no 'version' section */
35 	LIBBPF_ERRNO__ENDIAN,	/* Endian mismatch */
36 	LIBBPF_ERRNO__INTERNAL,	/* Internal error in libbpf */
37 	LIBBPF_ERRNO__RELOC,	/* Relocation failed */
38 	LIBBPF_ERRNO__LOAD,	/* Load program failure for unknown reason */
39 	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
40 	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
41 	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
42 	LIBBPF_ERRNO__PROGTYPE,	/* Kernel doesn't support this program type */
43 	LIBBPF_ERRNO__WRNGPID,	/* Wrong pid in netlink message */
44 	LIBBPF_ERRNO__INVSEQ,	/* Invalid netlink sequence */
45 	LIBBPF_ERRNO__NLPARSE,	/* netlink parsing error */
46 	__LIBBPF_ERRNO__END,
47 };
48 
49 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
50 
51 enum libbpf_print_level {
52         LIBBPF_WARN,
53         LIBBPF_INFO,
54         LIBBPF_DEBUG,
55 };
56 
57 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
58 				 const char *, va_list ap);
59 
60 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
61 
62 /* Hide internal to user */
63 struct bpf_object;
64 
65 struct bpf_object_open_attr {
66 	const char *file;
67 	enum bpf_prog_type prog_type;
68 };
69 
70 /* Helper macro to declare and initialize libbpf options struct
71  *
72  * This dance with uninitialized declaration, followed by memset to zero,
73  * followed by assignment using compound literal syntax is done to preserve
74  * ability to use a nice struct field initialization syntax and **hopefully**
75  * have all the padding bytes initialized to zero. It's not guaranteed though,
76  * when copying literal, that compiler won't copy garbage in literal's padding
77  * bytes, but that's the best way I've found and it seems to work in practice.
78  *
79  * Macro declares opts struct of given type and name, zero-initializes,
80  * including any extra padding, it with memset() and then assigns initial
81  * values provided by users in struct initializer-syntax as varargs.
82  */
83 #define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)				    \
84 	struct TYPE NAME = ({ 						    \
85 		memset(&NAME, 0, sizeof(struct TYPE));			    \
86 		(struct TYPE) {						    \
87 			.sz = sizeof(struct TYPE),			    \
88 			__VA_ARGS__					    \
89 		};							    \
90 	})
91 
92 struct bpf_object_open_opts {
93 	/* size of this struct, for forward/backward compatiblity */
94 	size_t sz;
95 	/* object name override, if provided:
96 	 * - for object open from file, this will override setting object
97 	 *   name from file path's base name;
98 	 * - for object open from memory buffer, this will specify an object
99 	 *   name and will override default "<addr>-<buf-size>" name;
100 	 */
101 	const char *object_name;
102 	/* parse map definitions non-strictly, allowing extra attributes/data */
103 	bool relaxed_maps;
104 	/* process CO-RE relocations non-strictly, allowing them to fail */
105 	bool relaxed_core_relocs;
106 	/* maps that set the 'pinning' attribute in their definition will have
107 	 * their pin_path attribute set to a file in this directory, and be
108 	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
109 	 */
110 	const char *pin_root_path;
111 	__u32 attach_prog_fd;
112 };
113 #define bpf_object_open_opts__last_field attach_prog_fd
114 
115 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
116 LIBBPF_API struct bpf_object *
117 bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts);
118 LIBBPF_API struct bpf_object *
119 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
120 		     struct bpf_object_open_opts *opts);
121 
122 /* deprecated bpf_object__open variants */
123 LIBBPF_API struct bpf_object *
124 bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
125 			const char *name);
126 LIBBPF_API struct bpf_object *
127 bpf_object__open_xattr(struct bpf_object_open_attr *attr);
128 
129 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
130 			     __u32 *size);
131 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
132 				__u32 *off);
133 
134 enum libbpf_pin_type {
135 	LIBBPF_PIN_NONE,
136 	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
137 	LIBBPF_PIN_BY_NAME,
138 };
139 
140 /* pin_maps and unpin_maps can both be called with a NULL path, in which case
141  * they will use the pin_path attribute of each map (and ignore all maps that
142  * don't have a pin_path set).
143  */
144 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
145 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
146 				      const char *path);
147 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
148 					const char *path);
149 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
150 					  const char *path);
151 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
152 LIBBPF_API void bpf_object__close(struct bpf_object *object);
153 
154 struct bpf_object_load_attr {
155 	struct bpf_object *obj;
156 	int log_level;
157 	const char *target_btf_path;
158 };
159 
160 /* Load/unload object into/from kernel */
161 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
162 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
163 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
164 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
165 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
166 
167 struct btf;
168 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
169 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
170 
171 LIBBPF_API struct bpf_program *
172 bpf_object__find_program_by_title(const struct bpf_object *obj,
173 				  const char *title);
174 
175 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
176 #define bpf_object__for_each_safe(pos, tmp)			\
177 	for ((pos) = bpf_object__next(NULL),		\
178 		(tmp) = bpf_object__next(pos);		\
179 	     (pos) != NULL;				\
180 	     (pos) = (tmp), (tmp) = bpf_object__next(tmp))
181 
182 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
183 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
184 				    bpf_object_clear_priv_t clear_priv);
185 LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);
186 
187 LIBBPF_API int
188 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
189 			 enum bpf_attach_type *expected_attach_type);
190 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
191 					  enum bpf_attach_type *attach_type);
192 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
193 					  enum bpf_attach_type attach_type);
194 
195 /* Accessors of bpf_program */
196 struct bpf_program;
197 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
198 						 const struct bpf_object *obj);
199 
200 #define bpf_object__for_each_program(pos, obj)		\
201 	for ((pos) = bpf_program__next(NULL, (obj));	\
202 	     (pos) != NULL;				\
203 	     (pos) = bpf_program__next((pos), (obj)))
204 
205 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
206 						 const struct bpf_object *obj);
207 
208 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
209 
210 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
211 				     bpf_program_clear_priv_t clear_priv);
212 
213 LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
214 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
215 					 __u32 ifindex);
216 
217 LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
218 					  bool needs_copy);
219 
220 /* returns program size in bytes */
221 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
222 
223 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
224 				 __u32 kern_version);
225 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
226 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
227 					 const char *path,
228 					 int instance);
229 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
230 					   const char *path,
231 					   int instance);
232 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
233 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
234 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
235 
236 struct bpf_link;
237 
238 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
239 
240 LIBBPF_API struct bpf_link *
241 bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
242 LIBBPF_API struct bpf_link *
243 bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
244 			   const char *func_name);
245 LIBBPF_API struct bpf_link *
246 bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
247 			   pid_t pid, const char *binary_path,
248 			   size_t func_offset);
249 LIBBPF_API struct bpf_link *
250 bpf_program__attach_tracepoint(struct bpf_program *prog,
251 			       const char *tp_category,
252 			       const char *tp_name);
253 LIBBPF_API struct bpf_link *
254 bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
255 				   const char *tp_name);
256 
257 LIBBPF_API struct bpf_link *
258 bpf_program__attach_trace(struct bpf_program *prog);
259 struct bpf_insn;
260 
261 /*
262  * Libbpf allows callers to adjust BPF programs before being loaded
263  * into kernel. One program in an object file can be transformed into
264  * multiple variants to be attached to different hooks.
265  *
266  * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
267  * form an API for this purpose.
268  *
269  * - bpf_program_prep_t:
270  *   Defines a 'preprocessor', which is a caller defined function
271  *   passed to libbpf through bpf_program__set_prep(), and will be
272  *   called before program is loaded. The processor should adjust
273  *   the program one time for each instance according to the instance id
274  *   passed to it.
275  *
276  * - bpf_program__set_prep:
277  *   Attaches a preprocessor to a BPF program. The number of instances
278  *   that should be created is also passed through this function.
279  *
280  * - bpf_program__nth_fd:
281  *   After the program is loaded, get resulting FD of a given instance
282  *   of the BPF program.
283  *
284  * If bpf_program__set_prep() is not used, the program would be loaded
285  * without adjustment during bpf_object__load(). The program has only
286  * one instance. In this case bpf_program__fd(prog) is equal to
287  * bpf_program__nth_fd(prog, 0).
288  */
289 
290 struct bpf_prog_prep_result {
291 	/*
292 	 * If not NULL, load new instruction array.
293 	 * If set to NULL, don't load this instance.
294 	 */
295 	struct bpf_insn *new_insn_ptr;
296 	int new_insn_cnt;
297 
298 	/* If not NULL, result FD is written to it. */
299 	int *pfd;
300 };
301 
302 /*
303  * Parameters of bpf_program_prep_t:
304  *  - prog:	The bpf_program being loaded.
305  *  - n:	Index of instance being generated.
306  *  - insns:	BPF instructions array.
307  *  - insns_cnt:Number of instructions in insns.
308  *  - res:	Output parameter, result of transformation.
309  *
310  * Return value:
311  *  - Zero:	pre-processing success.
312  *  - Non-zero:	pre-processing error, stop loading.
313  */
314 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
315 				  struct bpf_insn *insns, int insns_cnt,
316 				  struct bpf_prog_prep_result *res);
317 
318 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
319 				     bpf_program_prep_t prep);
320 
321 LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
322 
323 /*
324  * Adjust type of BPF program. Default is kprobe.
325  */
326 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
327 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
328 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
329 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
330 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
331 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
332 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
333 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
334 LIBBPF_API int bpf_program__set_tracing(struct bpf_program *prog);
335 
336 LIBBPF_API enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog);
337 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
338 				      enum bpf_prog_type type);
339 
340 LIBBPF_API enum bpf_attach_type
341 bpf_program__get_expected_attach_type(struct bpf_program *prog);
342 LIBBPF_API void
343 bpf_program__set_expected_attach_type(struct bpf_program *prog,
344 				      enum bpf_attach_type type);
345 
346 LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
347 LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
348 LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
349 LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
350 LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
351 LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
352 LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
353 LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
354 LIBBPF_API bool bpf_program__is_tracing(const struct bpf_program *prog);
355 
356 /*
357  * No need for __attribute__((packed)), all members of 'bpf_map_def'
358  * are all aligned.  In addition, using __attribute__((packed))
359  * would trigger a -Wpacked warning message, and lead to an error
360  * if -Werror is set.
361  */
362 struct bpf_map_def {
363 	unsigned int type;
364 	unsigned int key_size;
365 	unsigned int value_size;
366 	unsigned int max_entries;
367 	unsigned int map_flags;
368 };
369 
370 /*
371  * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
372  * so no need to worry about a name clash.
373  */
374 struct bpf_map;
375 LIBBPF_API struct bpf_map *
376 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
377 
378 LIBBPF_API int
379 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
380 
381 /*
382  * Get bpf_map through the offset of corresponding struct bpf_map_def
383  * in the BPF object file.
384  */
385 LIBBPF_API struct bpf_map *
386 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
387 
388 LIBBPF_API struct bpf_map *
389 bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
390 #define bpf_object__for_each_map(pos, obj)		\
391 	for ((pos) = bpf_map__next(NULL, (obj));	\
392 	     (pos) != NULL;				\
393 	     (pos) = bpf_map__next((pos), (obj)))
394 #define bpf_map__for_each bpf_object__for_each_map
395 
396 LIBBPF_API struct bpf_map *
397 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
398 
399 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
400 LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
401 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
402 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
403 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
404 
405 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
406 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
407 				 bpf_map_clear_priv_t clear_priv);
408 LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
409 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
410 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
411 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
412 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
413 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
414 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
415 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
416 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
417 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
418 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
419 
420 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
421 
422 LIBBPF_API long libbpf_get_error(const void *ptr);
423 
424 struct bpf_prog_load_attr {
425 	const char *file;
426 	enum bpf_prog_type prog_type;
427 	enum bpf_attach_type expected_attach_type;
428 	int ifindex;
429 	int log_level;
430 	int prog_flags;
431 };
432 
433 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
434 				   struct bpf_object **pobj, int *prog_fd);
435 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
436 			     struct bpf_object **pobj, int *prog_fd);
437 
438 struct xdp_link_info {
439 	__u32 prog_id;
440 	__u32 drv_prog_id;
441 	__u32 hw_prog_id;
442 	__u32 skb_prog_id;
443 	__u8 attach_mode;
444 };
445 
446 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
447 LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
448 LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
449 				     size_t info_size, __u32 flags);
450 
451 struct perf_buffer;
452 
453 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
454 				      void *data, __u32 size);
455 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
456 
457 /* common use perf buffer options */
458 struct perf_buffer_opts {
459 	/* if specified, sample_cb is called for each sample */
460 	perf_buffer_sample_fn sample_cb;
461 	/* if specified, lost_cb is called for each batch of lost samples */
462 	perf_buffer_lost_fn lost_cb;
463 	/* ctx is provided to sample_cb and lost_cb */
464 	void *ctx;
465 };
466 
467 LIBBPF_API struct perf_buffer *
468 perf_buffer__new(int map_fd, size_t page_cnt,
469 		 const struct perf_buffer_opts *opts);
470 
471 enum bpf_perf_event_ret {
472 	LIBBPF_PERF_EVENT_DONE	= 0,
473 	LIBBPF_PERF_EVENT_ERROR	= -1,
474 	LIBBPF_PERF_EVENT_CONT	= -2,
475 };
476 
477 struct perf_event_header;
478 
479 typedef enum bpf_perf_event_ret
480 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
481 
482 /* raw perf buffer options, giving most power and control */
483 struct perf_buffer_raw_opts {
484 	/* perf event attrs passed directly into perf_event_open() */
485 	struct perf_event_attr *attr;
486 	/* raw event callback */
487 	perf_buffer_event_fn event_cb;
488 	/* ctx is provided to event_cb */
489 	void *ctx;
490 	/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
491 	 * max_entries of given PERF_EVENT_ARRAY map)
492 	 */
493 	int cpu_cnt;
494 	/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
495 	int *cpus;
496 	/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
497 	int *map_keys;
498 };
499 
500 LIBBPF_API struct perf_buffer *
501 perf_buffer__new_raw(int map_fd, size_t page_cnt,
502 		     const struct perf_buffer_raw_opts *opts);
503 
504 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
505 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
506 
507 typedef enum bpf_perf_event_ret
508 	(*bpf_perf_event_print_t)(struct perf_event_header *hdr,
509 				  void *private_data);
510 LIBBPF_API enum bpf_perf_event_ret
511 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
512 			   void **copy_mem, size_t *copy_size,
513 			   bpf_perf_event_print_t fn, void *private_data);
514 
515 struct nlattr;
516 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
517 int libbpf_netlink_open(unsigned int *nl_pid);
518 int libbpf_nl_get_link(int sock, unsigned int nl_pid,
519 		       libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
520 int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
521 			libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
522 int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
523 			libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
524 int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
525 			 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
526 
527 struct bpf_prog_linfo;
528 struct bpf_prog_info;
529 
530 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
531 LIBBPF_API struct bpf_prog_linfo *
532 bpf_prog_linfo__new(const struct bpf_prog_info *info);
533 LIBBPF_API const struct bpf_line_info *
534 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
535 				__u64 addr, __u32 func_idx, __u32 nr_skip);
536 LIBBPF_API const struct bpf_line_info *
537 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
538 		      __u32 insn_off, __u32 nr_skip);
539 
540 /*
541  * Probe for supported system features
542  *
543  * Note that running many of these probes in a short amount of time can cause
544  * the kernel to reach the maximal size of lockable memory allowed for the
545  * user, causing subsequent probes to fail. In this case, the caller may want
546  * to adjust that limit with setrlimit().
547  */
548 LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
549 				    __u32 ifindex);
550 LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
551 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
552 				 enum bpf_prog_type prog_type, __u32 ifindex);
553 
554 /*
555  * Get bpf_prog_info in continuous memory
556  *
557  * struct bpf_prog_info has multiple arrays. The user has option to choose
558  * arrays to fetch from kernel. The following APIs provide an uniform way to
559  * fetch these data. All arrays in bpf_prog_info are stored in a single
560  * continuous memory region. This makes it easy to store the info in a
561  * file.
562  *
563  * Before writing bpf_prog_info_linear to files, it is necessary to
564  * translate pointers in bpf_prog_info to offsets. Helper functions
565  * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
566  * are introduced to switch between pointers and offsets.
567  *
568  * Examples:
569  *   # To fetch map_ids and prog_tags:
570  *   __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
571  *           (1UL << BPF_PROG_INFO_PROG_TAGS);
572  *   struct bpf_prog_info_linear *info_linear =
573  *           bpf_program__get_prog_info_linear(fd, arrays);
574  *
575  *   # To save data in file
576  *   bpf_program__bpil_addr_to_offs(info_linear);
577  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
578  *
579  *   # To read data from file
580  *   read(f, info_linear, <proper_size>);
581  *   bpf_program__bpil_offs_to_addr(info_linear);
582  */
583 enum bpf_prog_info_array {
584 	BPF_PROG_INFO_FIRST_ARRAY = 0,
585 	BPF_PROG_INFO_JITED_INSNS = 0,
586 	BPF_PROG_INFO_XLATED_INSNS,
587 	BPF_PROG_INFO_MAP_IDS,
588 	BPF_PROG_INFO_JITED_KSYMS,
589 	BPF_PROG_INFO_JITED_FUNC_LENS,
590 	BPF_PROG_INFO_FUNC_INFO,
591 	BPF_PROG_INFO_LINE_INFO,
592 	BPF_PROG_INFO_JITED_LINE_INFO,
593 	BPF_PROG_INFO_PROG_TAGS,
594 	BPF_PROG_INFO_LAST_ARRAY,
595 };
596 
597 struct bpf_prog_info_linear {
598 	/* size of struct bpf_prog_info, when the tool is compiled */
599 	__u32			info_len;
600 	/* total bytes allocated for data, round up to 8 bytes */
601 	__u32			data_len;
602 	/* which arrays are included in data */
603 	__u64			arrays;
604 	struct bpf_prog_info	info;
605 	__u8			data[];
606 };
607 
608 LIBBPF_API struct bpf_prog_info_linear *
609 bpf_program__get_prog_info_linear(int fd, __u64 arrays);
610 
611 LIBBPF_API void
612 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
613 
614 LIBBPF_API void
615 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
616 
617 /*
618  * A helper function to get the number of possible CPUs before looking up
619  * per-CPU maps. Negative errno is returned on failure.
620  *
621  * Example usage:
622  *
623  *     int ncpus = libbpf_num_possible_cpus();
624  *     if (ncpus < 0) {
625  *          // error handling
626  *     }
627  *     long values[ncpus];
628  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
629  *
630  */
631 LIBBPF_API int libbpf_num_possible_cpus(void);
632 
633 #ifdef __cplusplus
634 } /* extern "C" */
635 #endif
636 
637 #endif /* __LIBBPF_LIBBPF_H */
638