aboutsummaryrefslogtreecommitdiffstats
path: root/tools/lib/bpf/libbpf.h
blob: 1f3468dad8b2c300c3e8eeda9e94ca6f973d0faa (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */

/*
 * Common eBPF ELF object loading operations.
 *
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 */
#ifndef __LIBBPF_LIBBPF_H
#define __LIBBPF_LIBBPF_H

#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h>  // for size_t
#include <linux/bpf.h>

#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
#endif

enum libbpf_errno {
	__LIBBPF_ERRNO__START = 4000,

	/* Something wrong in libelf */
	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
	LIBBPF_ERRNO__FORMAT,	/* BPF object format invalid */
	LIBBPF_ERRNO__KVERSION,	/* Incorrect or no 'version' section */
	LIBBPF_ERRNO__ENDIAN,	/* Endian mismatch */
	LIBBPF_ERRNO__INTERNAL,	/* Internal error in libbpf */
	LIBBPF_ERRNO__RELOC,	/* Relocation failed */
	LIBBPF_ERRNO__LOAD,	/* Load program failure for unknown reason */
	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
	LIBBPF_ERRNO__PROGTYPE,	/* Kernel doesn't support this program type */
	LIBBPF_ERRNO__WRNGPID,	/* Wrong pid in netlink message */
	LIBBPF_ERRNO__INVSEQ,	/* Invalid netlink sequence */
	LIBBPF_ERRNO__NLPARSE,	/* netlink parsing error */
	__LIBBPF_ERRNO__END,
};

LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);

/*
 * __printf is defined in include/linux/compiler-gcc.h. However,
 * it would be better if libbpf.h didn't depend on Linux header files.
 * So instead of __printf, here we use gcc attribute directly.
 */
typedef int (*libbpf_print_fn_t)(const char *, ...)
	__attribute__((format(printf, 1, 2)));

LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn,
				 libbpf_print_fn_t info,
				 libbpf_print_fn_t debug);

/* Hide internal to user */
struct bpf_object;

struct bpf_object_open_attr {
	const char *file;
	enum bpf_prog_type prog_type;
};

LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
bpf_object__open_xattr(struct bpf_object_open_attr *attr);
struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
					    int flags);
LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf,
						      size_t obj_buf_sz,
						      const char *name);
LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
LIBBPF_API void bpf_object__close(struct bpf_object *object);

/* Load/unload object into/from kernel */
LIBBPF_API int bpf_object__load(struct bpf_object *obj);
LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
LIBBPF_API const char *bpf_object__name(struct bpf_object *obj);
LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj);
LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);

LIBBPF_API struct bpf_program *
bpf_object__find_program_by_title(struct bpf_object *obj, const char *title);

LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
#define bpf_object__for_each_safe(pos, tmp)			\
	for ((pos) = bpf_object__next(NULL),		\
		(tmp) = bpf_object__next(pos);		\
	     (pos) != NULL;				\
	     (pos) = (tmp), (tmp) = bpf_object__next(tmp))

typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
				    bpf_object_clear_priv_t clear_priv);
LIBBPF_API void *bpf_object__priv(struct bpf_object *prog);

LIBBPF_API int
libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
			 enum bpf_attach_type *expected_attach_type);
LIBBPF_API int libbpf_attach_type_by_name(const char *name,
					  enum bpf_attach_type *attach_type);

/* Accessors of bpf_program */
struct bpf_program;
LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
						 struct bpf_object *obj);

#define bpf_object__for_each_program(pos, obj)		\
	for ((pos) = bpf_program__next(NULL, (obj));	\
	     (pos) != NULL;				\
	     (pos) = bpf_program__next((pos), (obj)))

typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
					 void *);

LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
				     bpf_program_clear_priv_t clear_priv);

LIBBPF_API void *bpf_program__priv(struct bpf_program *prog);
LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
					 __u32 ifindex);

LIBBPF_API const char *bpf_program__title(struct bpf_program *prog,
					  bool needs_copy);

LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
				 __u32 kern_version);
LIBBPF_API int bpf_program__fd(struct bpf_program *prog);
LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
					 const char *path,
					 int instance);
LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
LIBBPF_API void bpf_program__unload(struct bpf_program *prog);

struct bpf_insn;

/*
 * Libbpf allows callers to adjust BPF programs before being loaded
 * into kernel. One program in an object file can be transformed into
 * multiple variants to be attached to different hooks.
 *
 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
 * form an API for this purpose.
 *
 * - bpf_program_prep_t:
 *   Defines a 'preprocessor', which is a caller defined function
 *   passed to libbpf through bpf_program__set_prep(), and will be
 *   called before program is loaded. The processor should adjust
 *   the program one time for each instance according to the instance id
 *   passed to it.
 *
 * - bpf_program__set_prep:
 *   Attaches a preprocessor to a BPF program. The number of instances
 *   that should be created is also passed through this function.
 *
 * - bpf_program__nth_fd:
 *   After the program is loaded, get resulting FD of a given instance
 *   of the BPF program.
 *
 * If bpf_program__set_prep() is not used, the program would be loaded
 * without adjustment during bpf_object__load(). The program has only
 * one instance. In this case bpf_program__fd(prog) is equal to
 * bpf_program__nth_fd(prog, 0).
 */

struct bpf_prog_prep_result {
	/*
	 * If not NULL, load new instruction array.
	 * If set to NULL, don't load this instance.
	 */
	struct bpf_insn *new_insn_ptr;
	int new_insn_cnt;

	/* If not NULL, result FD is written to it. */
	int *pfd;
};

/*
 * Parameters of bpf_program_prep_t:
 *  - prog:	The bpf_program being loaded.
 *  - n:	Index of instance being generated.
 *  - insns:	BPF instructions array.
 *  - insns_cnt:Number of instructions in insns.
 *  - res:	Output parameter, result of transformation.
 *
 * Return value:
 *  - Zero:	pre-processing success.
 *  - Non-zero:	pre-processing error, stop loading.
 */
typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
				  struct bpf_insn *insns, int insns_cnt,
				  struct bpf_prog_prep_result *res);

LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
				     bpf_program_prep_t prep);

LIBBPF_API int bpf_program__nth_fd(struct bpf_program *prog, int n);

/*
 * Adjust type of BPF program. Default is kprobe.
 */
LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
				      enum bpf_prog_type type);
LIBBPF_API void
bpf_program__set_expected_attach_type(struct bpf_program *prog,
				      enum bpf_attach_type type);

LIBBPF_API bool bpf_program__is_socket_filter(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_tracepoint(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_raw_tracepoint(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_kprobe(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_sched_cls(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_sched_act(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_xdp(struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_perf_event(struct bpf_program *prog);

/*
 * No need for __attribute__((packed)), all members of 'bpf_map_def'
 * are all aligned.  In addition, using __attribute__((packed))
 * would trigger a -Wpacked warning message, and lead to an error
 * if -Werror is set.
 */
struct bpf_map_def {
	unsigned int type;
	unsigned int key_size;
	unsigned int value_size;
	unsigned int max_entries;
	unsigned int map_flags;
};

/*
 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
 * so no need to worry about a name clash.
 */
struct bpf_map;
LIBBPF_API struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);

/*
 * Get bpf_map through the offset of corresponding struct bpf_map_def
 * in the BPF object file.
 */
LIBBPF_API struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);

LIBBPF_API struct bpf_map *
bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
#define bpf_map__for_each(pos, obj)		\
	for ((pos) = bpf_map__next(NULL, (obj));	\
	     (pos) != NULL;				\
	     (pos) = bpf_map__next((pos), (obj)))

LIBBPF_API int bpf_map__fd(struct bpf_map *map);
LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
LIBBPF_API const char *bpf_map__name(struct bpf_map *map);
LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);

typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
				 bpf_map_clear_priv_t clear_priv);
LIBBPF_API void *bpf_map__priv(struct bpf_map *map);
LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map);
LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);

LIBBPF_API long libbpf_get_error(const void *ptr);

struct bpf_prog_load_attr {
	const char *file;
	enum bpf_prog_type prog_type;
	enum bpf_attach_type expected_attach_type;
	int ifindex;
};

LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
				   struct bpf_object **pobj, int *prog_fd);
LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
			     struct bpf_object **pobj, int *prog_fd);

LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);

enum bpf_perf_event_ret {
	LIBBPF_PERF_EVENT_DONE	= 0,
	LIBBPF_PERF_EVENT_ERROR	= -1,
	LIBBPF_PERF_EVENT_CONT	= -2,
};

struct perf_event_header;
typedef enum bpf_perf_event_ret
	(*bpf_perf_event_print_t)(struct perf_event_header *hdr,
				  void *private_data);
LIBBPF_API enum bpf_perf_event_ret
bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
			   void **copy_mem, size_t *copy_size,
			   bpf_perf_event_print_t fn, void *private_data);

struct nlattr;
typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
int libbpf_netlink_open(unsigned int *nl_pid);
int libbpf_nl_get_link(int sock, unsigned int nl_pid,
		       libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
			libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
			libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
			 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
#endif /* __LIBBPF_LIBBPF_H */