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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#ifndef __BPF_LIBBPF_H
9#define __BPF_LIBBPF_H
10
11#include <stdio.h>
12#include <stdbool.h>
13#include <linux/err.h>
14
15enum libbpf_errno {
16 __LIBBPF_ERRNO__START = 4000,
17
18 /* Something wrong in libelf */
19 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
20 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
21 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
22 LIBBPF_ERRNO__ENDIAN, /* Endian missmatch */
23 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
24 LIBBPF_ERRNO__RELOC, /* Relocation failed */
25 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
26 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
27 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
28 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
29 __LIBBPF_ERRNO__END,
30};
31
32int libbpf_strerror(int err, char *buf, size_t size);
33
34/*
35 * In include/linux/compiler-gcc.h, __printf is defined. However
36 * it should be better if libbpf.h doesn't depend on Linux header file.
37 * So instead of __printf, here we use gcc attribute directly.
38 */
39typedef int (*libbpf_print_fn_t)(const char *, ...)
40 __attribute__((format(printf, 1, 2)));
41
42void libbpf_set_print(libbpf_print_fn_t warn,
43 libbpf_print_fn_t info,
44 libbpf_print_fn_t debug);
45
46/* Hide internal to user */
47struct bpf_object;
48
49struct bpf_object *bpf_object__open(const char *path);
50struct bpf_object *bpf_object__open_buffer(void *obj_buf,
51 size_t obj_buf_sz,
52 const char *name);
53void bpf_object__close(struct bpf_object *object);
54
55/* Load/unload object into/from kernel */
56int bpf_object__load(struct bpf_object *obj);
57int bpf_object__unload(struct bpf_object *obj);
58const char *bpf_object__get_name(struct bpf_object *obj);
59unsigned int bpf_object__get_kversion(struct bpf_object *obj);
60
61struct bpf_object *bpf_object__next(struct bpf_object *prev);
62#define bpf_object__for_each_safe(pos, tmp) \
63 for ((pos) = bpf_object__next(NULL), \
64 (tmp) = bpf_object__next(pos); \
65 (pos) != NULL; \
66 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
67
68/* Accessors of bpf_program. */
69struct bpf_program;
70struct bpf_program *bpf_program__next(struct bpf_program *prog,
71 struct bpf_object *obj);
72
73#define bpf_object__for_each_program(pos, obj) \
74 for ((pos) = bpf_program__next(NULL, (obj)); \
75 (pos) != NULL; \
76 (pos) = bpf_program__next((pos), (obj)))
77
78typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
79 void *);
80
81int bpf_program__set_private(struct bpf_program *prog, void *priv,
82 bpf_program_clear_priv_t clear_priv);
83
84int bpf_program__get_private(struct bpf_program *prog,
85 void **ppriv);
86
87const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
88
89int bpf_program__fd(struct bpf_program *prog);
90
91struct bpf_insn;
92
93/*
94 * Libbpf allows callers to adjust BPF programs before being loaded
95 * into kernel. One program in an object file can be transform into
96 * multiple variants to be attached to different code.
97 *
98 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
99 * are APIs for this propose.
100 *
101 * - bpf_program_prep_t:
102 * It defines 'preprocessor', which is a caller defined function
103 * passed to libbpf through bpf_program__set_prep(), and will be
104 * called before program is loaded. The processor should adjust
105 * the program one time for each instances according to the number
106 * passed to it.
107 *
108 * - bpf_program__set_prep:
109 * Attachs a preprocessor to a BPF program. The number of instances
110 * whould be created is also passed through this function.
111 *
112 * - bpf_program__nth_fd:
113 * After the program is loaded, get resuling fds from bpf program for
114 * each instances.
115 *
116 * If bpf_program__set_prep() is not used, the program whould be loaded
117 * without adjustment during bpf_object__load(). The program has only
118 * one instance. In this case bpf_program__fd(prog) is equal to
119 * bpf_program__nth_fd(prog, 0).
120 */
121
122struct bpf_prog_prep_result {
123 /*
124 * If not NULL, load new instruction array.
125 * If set to NULL, don't load this instance.
126 */
127 struct bpf_insn *new_insn_ptr;
128 int new_insn_cnt;
129
130 /* If not NULL, result fd is set to it */
131 int *pfd;
132};
133
134/*
135 * Parameters of bpf_program_prep_t:
136 * - prog: The bpf_program being loaded.
137 * - n: Index of instance being generated.
138 * - insns: BPF instructions array.
139 * - insns_cnt:Number of instructions in insns.
140 * - res: Output parameter, result of transformation.
141 *
142 * Return value:
143 * - Zero: pre-processing success.
144 * - Non-zero: pre-processing, stop loading.
145 */
146typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
147 struct bpf_insn *insns, int insns_cnt,
148 struct bpf_prog_prep_result *res);
149
150int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
151 bpf_program_prep_t prep);
152
153int bpf_program__nth_fd(struct bpf_program *prog, int n);
154
155/*
156 * We don't need __attribute__((packed)) now since it is
157 * unnecessary for 'bpf_map_def' because they are all aligned.
158 * In addition, using it will trigger -Wpacked warning message,
159 * and will be treated as an error due to -Werror.
160 */
161struct bpf_map_def {
162 unsigned int type;
163 unsigned int key_size;
164 unsigned int value_size;
165 unsigned int max_entries;
166};
167
168/*
169 * There is another 'struct bpf_map' in include/linux/map.h. However,
170 * it is not a uapi header so no need to consider name clash.
171 */
172struct bpf_map;
173struct bpf_map *
174bpf_object__get_map_by_name(struct bpf_object *obj, const char *name);
175
176struct bpf_map *
177bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
178#define bpf_map__for_each(pos, obj) \
179 for ((pos) = bpf_map__next(NULL, (obj)); \
180 (pos) != NULL; \
181 (pos) = bpf_map__next((pos), (obj)))
182
183int bpf_map__get_fd(struct bpf_map *map);
184int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef);
185const char *bpf_map__get_name(struct bpf_map *map);
186
187typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
188int bpf_map__set_private(struct bpf_map *map, void *priv,
189 bpf_map_clear_priv_t clear_priv);
190int bpf_map__get_private(struct bpf_map *map, void **ppriv);
191
192#endif