2 * Common eBPF ELF object loading operations.
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.
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!)
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.
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>
21 #ifndef __BPF_LIBBPF_H
22 #define __BPF_LIBBPF_H
27 #include <sys/types.h> // for size_t
30 __LIBBPF_ERRNO__START = 4000,
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 */
47 int libbpf_strerror(int err, char *buf, size_t size);
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.
54 typedef int (*libbpf_print_fn_t)(const char *, ...)
55 __attribute__((format(printf, 1, 2)));
57 void libbpf_set_print(libbpf_print_fn_t warn,
58 libbpf_print_fn_t info,
59 libbpf_print_fn_t debug);
61 /* Hide internal to user */
64 struct bpf_object *bpf_object__open(const char *path);
65 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
68 void bpf_object__close(struct bpf_object *object);
70 /* Load/unload object into/from kernel */
71 int bpf_object__load(struct bpf_object *obj);
72 int bpf_object__unload(struct bpf_object *obj);
73 const char *bpf_object__name(struct bpf_object *obj);
74 unsigned int bpf_object__kversion(struct bpf_object *obj);
76 struct 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); \
81 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
83 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
84 int bpf_object__set_priv(struct bpf_object *obj, void *priv,
85 bpf_object_clear_priv_t clear_priv);
86 void *bpf_object__priv(struct bpf_object *prog);
88 /* Accessors of bpf_program. */
90 struct bpf_program *bpf_program__next(struct bpf_program *prog,
91 struct bpf_object *obj);
93 #define bpf_object__for_each_program(pos, obj) \
94 for ((pos) = bpf_program__next(NULL, (obj)); \
96 (pos) = bpf_program__next((pos), (obj)))
98 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
101 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
102 bpf_program_clear_priv_t clear_priv);
104 void *bpf_program__priv(struct bpf_program *prog);
106 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
108 int bpf_program__fd(struct bpf_program *prog);
109 int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
111 int bpf_program__pin(struct bpf_program *prog, const char *path);
116 * Libbpf allows callers to adjust BPF programs before being loaded
117 * into kernel. One program in an object file can be transform into
118 * multiple variants to be attached to different code.
120 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
121 * are APIs for this propose.
123 * - bpf_program_prep_t:
124 * It defines 'preprocessor', which is a caller defined function
125 * passed to libbpf through bpf_program__set_prep(), and will be
126 * called before program is loaded. The processor should adjust
127 * the program one time for each instances according to the number
130 * - bpf_program__set_prep:
131 * Attachs a preprocessor to a BPF program. The number of instances
132 * whould be created is also passed through this function.
134 * - bpf_program__nth_fd:
135 * After the program is loaded, get resuling fds from bpf program for
138 * If bpf_program__set_prep() is not used, the program whould be loaded
139 * without adjustment during bpf_object__load(). The program has only
140 * one instance. In this case bpf_program__fd(prog) is equal to
141 * bpf_program__nth_fd(prog, 0).
144 struct bpf_prog_prep_result {
146 * If not NULL, load new instruction array.
147 * If set to NULL, don't load this instance.
149 struct bpf_insn *new_insn_ptr;
152 /* If not NULL, result fd is set to it */
157 * Parameters of bpf_program_prep_t:
158 * - prog: The bpf_program being loaded.
159 * - n: Index of instance being generated.
160 * - insns: BPF instructions array.
161 * - insns_cnt:Number of instructions in insns.
162 * - res: Output parameter, result of transformation.
165 * - Zero: pre-processing success.
166 * - Non-zero: pre-processing, stop loading.
168 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
169 struct bpf_insn *insns, int insns_cnt,
170 struct bpf_prog_prep_result *res);
172 int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
173 bpf_program_prep_t prep);
175 int bpf_program__nth_fd(struct bpf_program *prog, int n);
178 * Adjust type of bpf program. Default is kprobe.
180 int bpf_program__set_socket_filter(struct bpf_program *prog);
181 int bpf_program__set_tracepoint(struct bpf_program *prog);
182 int bpf_program__set_kprobe(struct bpf_program *prog);
183 int bpf_program__set_sched_cls(struct bpf_program *prog);
184 int bpf_program__set_sched_act(struct bpf_program *prog);
185 int bpf_program__set_xdp(struct bpf_program *prog);
186 int bpf_program__set_perf_event(struct bpf_program *prog);
188 bool bpf_program__is_socket_filter(struct bpf_program *prog);
189 bool bpf_program__is_tracepoint(struct bpf_program *prog);
190 bool bpf_program__is_kprobe(struct bpf_program *prog);
191 bool bpf_program__is_sched_cls(struct bpf_program *prog);
192 bool bpf_program__is_sched_act(struct bpf_program *prog);
193 bool bpf_program__is_xdp(struct bpf_program *prog);
194 bool bpf_program__is_perf_event(struct bpf_program *prog);
197 * We don't need __attribute__((packed)) now since it is
198 * unnecessary for 'bpf_map_def' because they are all aligned.
199 * In addition, using it will trigger -Wpacked warning message,
200 * and will be treated as an error due to -Werror.
204 unsigned int key_size;
205 unsigned int value_size;
206 unsigned int max_entries;
210 * There is another 'struct bpf_map' in include/linux/map.h. However,
211 * it is not a uapi header so no need to consider name clash.
215 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
218 * Get bpf_map through the offset of corresponding struct bpf_map_def
219 * in the bpf object file.
222 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
225 bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
226 #define bpf_map__for_each(pos, obj) \
227 for ((pos) = bpf_map__next(NULL, (obj)); \
229 (pos) = bpf_map__next((pos), (obj)))
231 int bpf_map__fd(struct bpf_map *map);
232 const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
233 const char *bpf_map__name(struct bpf_map *map);
235 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
236 int bpf_map__set_priv(struct bpf_map *map, void *priv,
237 bpf_map_clear_priv_t clear_priv);
238 void *bpf_map__priv(struct bpf_map *map);
240 long libbpf_get_error(const void *ptr);