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Eric Leblond6061a3d2018-01-30 21:55:03 +01001/* SPDX-License-Identifier: LGPL-2.1 */
2
Wang Nan1b76c132015-07-01 02:13:51 +00003/*
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.
Wang Nan203d1ca2016-07-04 11:02:42 +00009 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation;
13 * version 2.1 of the License (not later!)
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this program; if not, see <http://www.gnu.org/licenses>
Wang Nan1b76c132015-07-01 02:13:51 +000022 */
23#ifndef __BPF_LIBBPF_H
24#define __BPF_LIBBPF_H
25
Wang Nan1a5e3fb2015-07-01 02:13:53 +000026#include <stdio.h>
Joe Stringere28ff1a2017-01-22 17:11:25 -080027#include <stdint.h>
Wang Nanaa9b1ac2015-07-01 02:14:08 +000028#include <stdbool.h>
Wang Nan5a6acad12016-11-26 07:03:27 +000029#include <sys/types.h> // for size_t
Alexei Starovoitovdd26b7f2017-03-30 21:45:40 -070030#include <linux/bpf.h>
Wang Nan6371ca3b2015-11-06 13:49:37 +000031
32enum libbpf_errno {
33 __LIBBPF_ERRNO__START = 4000,
34
35 /* Something wrong in libelf */
36 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
37 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
38 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
Colin Ian Kingde8a63b2016-06-28 13:23:37 +010039 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
Wang Nan6371ca3b2015-11-06 13:49:37 +000040 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
41 LIBBPF_ERRNO__RELOC, /* Relocation failed */
42 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
43 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
44 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
45 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
Wang Nan705fa212016-07-13 10:44:02 +000046 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
Eric Leblond949abbe2018-01-30 21:55:01 +010047 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
48 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
Wang Nan6371ca3b2015-11-06 13:49:37 +000049 __LIBBPF_ERRNO__END,
50};
51
52int libbpf_strerror(int err, char *buf, size_t size);
Wang Nan1a5e3fb2015-07-01 02:13:53 +000053
Wang Nanb3f59d62015-07-01 02:13:52 +000054/*
55 * In include/linux/compiler-gcc.h, __printf is defined. However
56 * it should be better if libbpf.h doesn't depend on Linux header file.
57 * So instead of __printf, here we use gcc attribute directly.
58 */
59typedef int (*libbpf_print_fn_t)(const char *, ...)
60 __attribute__((format(printf, 1, 2)));
61
62void libbpf_set_print(libbpf_print_fn_t warn,
63 libbpf_print_fn_t info,
64 libbpf_print_fn_t debug);
65
Wang Nan1a5e3fb2015-07-01 02:13:53 +000066/* Hide internal to user */
67struct bpf_object;
68
69struct bpf_object *bpf_object__open(const char *path);
Wang Nan6c956392015-07-01 02:13:54 +000070struct bpf_object *bpf_object__open_buffer(void *obj_buf,
Wang Nanacf860a2015-08-27 02:30:55 +000071 size_t obj_buf_sz,
72 const char *name);
Joe Stringerd5148d82017-01-26 13:19:58 -080073int bpf_object__pin(struct bpf_object *object, const char *path);
Wang Nan1a5e3fb2015-07-01 02:13:53 +000074void bpf_object__close(struct bpf_object *object);
75
Wang Nan52d33522015-07-01 02:14:04 +000076/* Load/unload object into/from kernel */
77int bpf_object__load(struct bpf_object *obj);
78int bpf_object__unload(struct bpf_object *obj);
Arnaldo Carvalho de Meloa7fe0452016-06-03 12:22:51 -030079const char *bpf_object__name(struct bpf_object *obj);
80unsigned int bpf_object__kversion(struct bpf_object *obj);
Wang Nan52d33522015-07-01 02:14:04 +000081
Wang Nan9a208ef2015-07-01 02:14:10 +000082struct bpf_object *bpf_object__next(struct bpf_object *prev);
83#define bpf_object__for_each_safe(pos, tmp) \
84 for ((pos) = bpf_object__next(NULL), \
85 (tmp) = bpf_object__next(pos); \
86 (pos) != NULL; \
87 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
88
Wang Nan10931d22016-11-26 07:03:26 +000089typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
90int bpf_object__set_priv(struct bpf_object *obj, void *priv,
91 bpf_object_clear_priv_t clear_priv);
92void *bpf_object__priv(struct bpf_object *prog);
93
Wang Nanaa9b1ac2015-07-01 02:14:08 +000094/* Accessors of bpf_program. */
95struct bpf_program;
96struct bpf_program *bpf_program__next(struct bpf_program *prog,
97 struct bpf_object *obj);
98
99#define bpf_object__for_each_program(pos, obj) \
100 for ((pos) = bpf_program__next(NULL, (obj)); \
101 (pos) != NULL; \
102 (pos) = bpf_program__next((pos), (obj)))
103
104typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
105 void *);
106
Arnaldo Carvalho de Meloedb13ed2016-06-03 12:38:21 -0300107int bpf_program__set_priv(struct bpf_program *prog, void *priv,
108 bpf_program_clear_priv_t clear_priv);
Wang Nanaa9b1ac2015-07-01 02:14:08 +0000109
Arnaldo Carvalho de Melobe834ff2016-06-03 12:36:39 -0300110void *bpf_program__priv(struct bpf_program *prog);
Wang Nanaa9b1ac2015-07-01 02:14:08 +0000111
Namhyung Kim715f8db2015-11-03 20:21:05 +0900112const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
Wang Nanaa9b1ac2015-07-01 02:14:08 +0000113
114int bpf_program__fd(struct bpf_program *prog);
Joe Stringerf3675402017-01-26 13:19:56 -0800115int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
116 int instance);
117int bpf_program__pin(struct bpf_program *prog, const char *path);
Wang Nanaa9b1ac2015-07-01 02:14:08 +0000118
Wang Nanb5805632015-11-16 12:10:09 +0000119struct bpf_insn;
120
121/*
122 * Libbpf allows callers to adjust BPF programs before being loaded
123 * into kernel. One program in an object file can be transform into
124 * multiple variants to be attached to different code.
125 *
126 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
127 * are APIs for this propose.
128 *
129 * - bpf_program_prep_t:
130 * It defines 'preprocessor', which is a caller defined function
131 * passed to libbpf through bpf_program__set_prep(), and will be
132 * called before program is loaded. The processor should adjust
133 * the program one time for each instances according to the number
134 * passed to it.
135 *
136 * - bpf_program__set_prep:
137 * Attachs a preprocessor to a BPF program. The number of instances
138 * whould be created is also passed through this function.
139 *
140 * - bpf_program__nth_fd:
141 * After the program is loaded, get resuling fds from bpf program for
142 * each instances.
143 *
144 * If bpf_program__set_prep() is not used, the program whould be loaded
145 * without adjustment during bpf_object__load(). The program has only
146 * one instance. In this case bpf_program__fd(prog) is equal to
147 * bpf_program__nth_fd(prog, 0).
148 */
149
150struct bpf_prog_prep_result {
151 /*
152 * If not NULL, load new instruction array.
153 * If set to NULL, don't load this instance.
154 */
155 struct bpf_insn *new_insn_ptr;
156 int new_insn_cnt;
157
158 /* If not NULL, result fd is set to it */
159 int *pfd;
160};
161
162/*
163 * Parameters of bpf_program_prep_t:
164 * - prog: The bpf_program being loaded.
165 * - n: Index of instance being generated.
166 * - insns: BPF instructions array.
167 * - insns_cnt:Number of instructions in insns.
168 * - res: Output parameter, result of transformation.
169 *
170 * Return value:
171 * - Zero: pre-processing success.
172 * - Non-zero: pre-processing, stop loading.
173 */
174typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
175 struct bpf_insn *insns, int insns_cnt,
176 struct bpf_prog_prep_result *res);
177
178int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
179 bpf_program_prep_t prep);
180
181int bpf_program__nth_fd(struct bpf_program *prog, int n);
182
Wang Nan34090912015-07-01 02:14:02 +0000183/*
Wang Nan5f44e4c82016-07-13 10:44:01 +0000184 * Adjust type of bpf program. Default is kprobe.
185 */
Joe Stringer7803ba72017-01-22 17:11:24 -0800186int bpf_program__set_socket_filter(struct bpf_program *prog);
Wang Nan5f44e4c82016-07-13 10:44:01 +0000187int bpf_program__set_tracepoint(struct bpf_program *prog);
188int bpf_program__set_kprobe(struct bpf_program *prog);
Joe Stringer7803ba72017-01-22 17:11:24 -0800189int bpf_program__set_sched_cls(struct bpf_program *prog);
190int bpf_program__set_sched_act(struct bpf_program *prog);
191int bpf_program__set_xdp(struct bpf_program *prog);
192int bpf_program__set_perf_event(struct bpf_program *prog);
Alexei Starovoitovdd26b7f2017-03-30 21:45:40 -0700193void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type);
Wang Nan5f44e4c82016-07-13 10:44:01 +0000194
Joe Stringer7803ba72017-01-22 17:11:24 -0800195bool bpf_program__is_socket_filter(struct bpf_program *prog);
Wang Nan5f44e4c82016-07-13 10:44:01 +0000196bool bpf_program__is_tracepoint(struct bpf_program *prog);
197bool bpf_program__is_kprobe(struct bpf_program *prog);
Joe Stringer7803ba72017-01-22 17:11:24 -0800198bool bpf_program__is_sched_cls(struct bpf_program *prog);
199bool bpf_program__is_sched_act(struct bpf_program *prog);
200bool bpf_program__is_xdp(struct bpf_program *prog);
201bool bpf_program__is_perf_event(struct bpf_program *prog);
Wang Nan5f44e4c82016-07-13 10:44:01 +0000202
203/*
Wang Nan34090912015-07-01 02:14:02 +0000204 * We don't need __attribute__((packed)) now since it is
205 * unnecessary for 'bpf_map_def' because they are all aligned.
206 * In addition, using it will trigger -Wpacked warning message,
207 * and will be treated as an error due to -Werror.
208 */
209struct bpf_map_def {
210 unsigned int type;
211 unsigned int key_size;
212 unsigned int value_size;
213 unsigned int max_entries;
Craig Gallekfe9b5f72017-10-05 10:41:58 -0400214 unsigned int map_flags;
Wang Nan34090912015-07-01 02:14:02 +0000215};
216
Wang Nan9d759a92015-11-27 08:47:35 +0000217/*
218 * There is another 'struct bpf_map' in include/linux/map.h. However,
219 * it is not a uapi header so no need to consider name clash.
220 */
221struct bpf_map;
Wang Nan561bbcc2015-11-27 08:47:36 +0000222struct bpf_map *
Arnaldo Carvalho de Meloa7fe0452016-06-03 12:22:51 -0300223bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
Wang Nan9d759a92015-11-27 08:47:35 +0000224
Wang Nan5a6acad12016-11-26 07:03:27 +0000225/*
226 * Get bpf_map through the offset of corresponding struct bpf_map_def
227 * in the bpf object file.
228 */
229struct bpf_map *
230bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
231
Wang Nan9d759a92015-11-27 08:47:35 +0000232struct bpf_map *
233bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
234#define bpf_map__for_each(pos, obj) \
235 for ((pos) = bpf_map__next(NULL, (obj)); \
236 (pos) != NULL; \
237 (pos) = bpf_map__next((pos), (obj)))
238
Arnaldo Carvalho de Melo6e009e652016-06-03 12:15:52 -0300239int bpf_map__fd(struct bpf_map *map);
Arnaldo Carvalho de Melo53897a72016-06-02 14:21:06 -0300240const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
Arnaldo Carvalho de Melo009ad5d2016-06-02 11:02:05 -0300241const char *bpf_map__name(struct bpf_map *map);
Wang Nan9d759a92015-11-27 08:47:35 +0000242
243typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
Arnaldo Carvalho de Meloedb13ed2016-06-03 12:38:21 -0300244int bpf_map__set_priv(struct bpf_map *map, void *priv,
245 bpf_map_clear_priv_t clear_priv);
Arnaldo Carvalho de Melob4cbfa52016-06-02 10:51:59 -0300246void *bpf_map__priv(struct bpf_map *map);
Joe Stringerb6989f32017-01-26 13:19:57 -0800247int bpf_map__pin(struct bpf_map *map, const char *path);
Wang Nan9d759a92015-11-27 08:47:35 +0000248
Joe Stringere28ff1a2017-01-22 17:11:25 -0800249long libbpf_get_error(const void *ptr);
250
Andrey Ignatovd7be1432018-03-30 15:08:01 -0700251struct bpf_prog_load_attr {
252 const char *file;
253 enum bpf_prog_type prog_type;
254 enum bpf_attach_type expected_attach_type;
255};
256
257int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
258 struct bpf_object **pobj, int *prog_fd);
John Fastabend6f6d33f2017-08-15 22:34:22 -0700259int bpf_prog_load(const char *file, enum bpf_prog_type type,
260 struct bpf_object **pobj, int *prog_fd);
Eric Leblond949abbe2018-01-30 21:55:01 +0100261
262int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
Wang Nan1b76c132015-07-01 02:13:51 +0000263#endif