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1/* SPDX-License-Identifier: LGPL-2.1 */
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 * 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>
22 */
23#ifndef __BPF_LIBBPF_H
24#define __BPF_LIBBPF_H
25
26#include <stdio.h>
27#include <stdint.h>
28#include <stdbool.h>
29#include <sys/types.h> // for size_t
30#include <linux/bpf.h>
31
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 */
39 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
40 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 */
46 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
47 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
48 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
49 __LIBBPF_ERRNO__END,
50};
51
52int libbpf_strerror(int err, char *buf, size_t size);
53
54/*
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
66/* Hide internal to user */
67struct bpf_object;
68
69struct bpf_object *bpf_object__open(const char *path);
70struct bpf_object *bpf_object__open_buffer(void *obj_buf,
71 size_t obj_buf_sz,
72 const char *name);
73int bpf_object__pin(struct bpf_object *object, const char *path);
74void bpf_object__close(struct bpf_object *object);
75
76/* Load/unload object into/from kernel */
77int bpf_object__load(struct bpf_object *obj);
78int bpf_object__unload(struct bpf_object *obj);
79const char *bpf_object__name(struct bpf_object *obj);
80unsigned int bpf_object__kversion(struct bpf_object *obj);
81
82struct 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
89typedef 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
94/* 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
107int bpf_program__set_priv(struct bpf_program *prog, void *priv,
108 bpf_program_clear_priv_t clear_priv);
109
110void *bpf_program__priv(struct bpf_program *prog);
111
112const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
113
114int bpf_program__fd(struct bpf_program *prog);
115int 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);
118
119struct 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
183/*
184 * Adjust type of bpf program. Default is kprobe.
185 */
186int bpf_program__set_socket_filter(struct bpf_program *prog);
187int bpf_program__set_tracepoint(struct bpf_program *prog);
188int bpf_program__set_kprobe(struct bpf_program *prog);
189int 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);
193void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type);
194
195bool bpf_program__is_socket_filter(struct bpf_program *prog);
196bool bpf_program__is_tracepoint(struct bpf_program *prog);
197bool bpf_program__is_kprobe(struct bpf_program *prog);
198bool 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);
202
203/*
204 * 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;
214 unsigned int map_flags;
215};
216
217/*
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;
222struct bpf_map *
223bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
224
225/*
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
232struct 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
239int bpf_map__fd(struct bpf_map *map);
240const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
241const char *bpf_map__name(struct bpf_map *map);
242
243typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
244int bpf_map__set_priv(struct bpf_map *map, void *priv,
245 bpf_map_clear_priv_t clear_priv);
246void *bpf_map__priv(struct bpf_map *map);
247int bpf_map__pin(struct bpf_map *map, const char *path);
248
249long libbpf_get_error(const void *ptr);
250
251struct 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);
259int bpf_prog_load(const char *file, enum bpf_prog_type type,
260 struct bpf_object **pobj, int *prog_fd);
261
262int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
263#endif
1/*
2 * Common eBPF ELF object loading operations.
3 *
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation;
11 * version 2.1 of the License (not later!)
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this program; if not, see <http://www.gnu.org/licenses>
20 */
21#ifndef __BPF_LIBBPF_H
22#define __BPF_LIBBPF_H
23
24#include <stdio.h>
25#include <stdbool.h>
26#include <linux/err.h>
27#include <sys/types.h> // for size_t
28
29enum libbpf_errno {
30 __LIBBPF_ERRNO__START = 4000,
31
32 /* Something wrong in libelf */
33 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
34 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
35 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
36 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
37 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
38 LIBBPF_ERRNO__RELOC, /* Relocation failed */
39 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
40 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
41 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
42 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
43 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
44 __LIBBPF_ERRNO__END,
45};
46
47int libbpf_strerror(int err, char *buf, size_t size);
48
49/*
50 * In include/linux/compiler-gcc.h, __printf is defined. However
51 * it should be better if libbpf.h doesn't depend on Linux header file.
52 * So instead of __printf, here we use gcc attribute directly.
53 */
54typedef int (*libbpf_print_fn_t)(const char *, ...)
55 __attribute__((format(printf, 1, 2)));
56
57void libbpf_set_print(libbpf_print_fn_t warn,
58 libbpf_print_fn_t info,
59 libbpf_print_fn_t debug);
60
61/* Hide internal to user */
62struct bpf_object;
63
64struct bpf_object *bpf_object__open(const char *path);
65struct bpf_object *bpf_object__open_buffer(void *obj_buf,
66 size_t obj_buf_sz,
67 const char *name);
68void bpf_object__close(struct bpf_object *object);
69
70/* Load/unload object into/from kernel */
71int bpf_object__load(struct bpf_object *obj);
72int bpf_object__unload(struct bpf_object *obj);
73const char *bpf_object__name(struct bpf_object *obj);
74unsigned int bpf_object__kversion(struct bpf_object *obj);
75
76struct bpf_object *bpf_object__next(struct bpf_object *prev);
77#define bpf_object__for_each_safe(pos, tmp) \
78 for ((pos) = bpf_object__next(NULL), \
79 (tmp) = bpf_object__next(pos); \
80 (pos) != NULL; \
81 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
82
83typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
84int bpf_object__set_priv(struct bpf_object *obj, void *priv,
85 bpf_object_clear_priv_t clear_priv);
86void *bpf_object__priv(struct bpf_object *prog);
87
88/* Accessors of bpf_program. */
89struct bpf_program;
90struct bpf_program *bpf_program__next(struct bpf_program *prog,
91 struct bpf_object *obj);
92
93#define bpf_object__for_each_program(pos, obj) \
94 for ((pos) = bpf_program__next(NULL, (obj)); \
95 (pos) != NULL; \
96 (pos) = bpf_program__next((pos), (obj)))
97
98typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
99 void *);
100
101int bpf_program__set_priv(struct bpf_program *prog, void *priv,
102 bpf_program_clear_priv_t clear_priv);
103
104void *bpf_program__priv(struct bpf_program *prog);
105
106const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
107
108int bpf_program__fd(struct bpf_program *prog);
109
110struct bpf_insn;
111
112/*
113 * Libbpf allows callers to adjust BPF programs before being loaded
114 * into kernel. One program in an object file can be transform into
115 * multiple variants to be attached to different code.
116 *
117 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
118 * are APIs for this propose.
119 *
120 * - bpf_program_prep_t:
121 * It defines 'preprocessor', which is a caller defined function
122 * passed to libbpf through bpf_program__set_prep(), and will be
123 * called before program is loaded. The processor should adjust
124 * the program one time for each instances according to the number
125 * passed to it.
126 *
127 * - bpf_program__set_prep:
128 * Attachs a preprocessor to a BPF program. The number of instances
129 * whould be created is also passed through this function.
130 *
131 * - bpf_program__nth_fd:
132 * After the program is loaded, get resuling fds from bpf program for
133 * each instances.
134 *
135 * If bpf_program__set_prep() is not used, the program whould be loaded
136 * without adjustment during bpf_object__load(). The program has only
137 * one instance. In this case bpf_program__fd(prog) is equal to
138 * bpf_program__nth_fd(prog, 0).
139 */
140
141struct bpf_prog_prep_result {
142 /*
143 * If not NULL, load new instruction array.
144 * If set to NULL, don't load this instance.
145 */
146 struct bpf_insn *new_insn_ptr;
147 int new_insn_cnt;
148
149 /* If not NULL, result fd is set to it */
150 int *pfd;
151};
152
153/*
154 * Parameters of bpf_program_prep_t:
155 * - prog: The bpf_program being loaded.
156 * - n: Index of instance being generated.
157 * - insns: BPF instructions array.
158 * - insns_cnt:Number of instructions in insns.
159 * - res: Output parameter, result of transformation.
160 *
161 * Return value:
162 * - Zero: pre-processing success.
163 * - Non-zero: pre-processing, stop loading.
164 */
165typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
166 struct bpf_insn *insns, int insns_cnt,
167 struct bpf_prog_prep_result *res);
168
169int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
170 bpf_program_prep_t prep);
171
172int bpf_program__nth_fd(struct bpf_program *prog, int n);
173
174/*
175 * Adjust type of bpf program. Default is kprobe.
176 */
177int bpf_program__set_tracepoint(struct bpf_program *prog);
178int bpf_program__set_kprobe(struct bpf_program *prog);
179
180bool bpf_program__is_tracepoint(struct bpf_program *prog);
181bool bpf_program__is_kprobe(struct bpf_program *prog);
182
183/*
184 * We don't need __attribute__((packed)) now since it is
185 * unnecessary for 'bpf_map_def' because they are all aligned.
186 * In addition, using it will trigger -Wpacked warning message,
187 * and will be treated as an error due to -Werror.
188 */
189struct bpf_map_def {
190 unsigned int type;
191 unsigned int key_size;
192 unsigned int value_size;
193 unsigned int max_entries;
194};
195
196/*
197 * There is another 'struct bpf_map' in include/linux/map.h. However,
198 * it is not a uapi header so no need to consider name clash.
199 */
200struct bpf_map;
201struct bpf_map *
202bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
203
204/*
205 * Get bpf_map through the offset of corresponding struct bpf_map_def
206 * in the bpf object file.
207 */
208struct bpf_map *
209bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
210
211struct bpf_map *
212bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
213#define bpf_map__for_each(pos, obj) \
214 for ((pos) = bpf_map__next(NULL, (obj)); \
215 (pos) != NULL; \
216 (pos) = bpf_map__next((pos), (obj)))
217
218int bpf_map__fd(struct bpf_map *map);
219const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
220const char *bpf_map__name(struct bpf_map *map);
221
222typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
223int bpf_map__set_priv(struct bpf_map *map, void *priv,
224 bpf_map_clear_priv_t clear_priv);
225void *bpf_map__priv(struct bpf_map *map);
226
227#endif