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
26 #include <linux/err.h>
29 __LIBBPF_ERRNO__START = 4000,
31 /* Something wrong in libelf */
32 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
33 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
34 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
35 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
36 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
37 LIBBPF_ERRNO__RELOC, /* Relocation failed */
38 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
39 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
40 LIBBPF_ERRNO__PROG2BIG, /* Program too big */
41 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
42 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
46 int libbpf_strerror(int err, char *buf, size_t size);
49 * In include/linux/compiler-gcc.h, __printf is defined. However
50 * it should be better if libbpf.h doesn't depend on Linux header file.
51 * So instead of __printf, here we use gcc attribute directly.
53 typedef int (*libbpf_print_fn_t)(const char *, ...)
54 __attribute__((format(printf, 1, 2)));
56 void libbpf_set_print(libbpf_print_fn_t warn,
57 libbpf_print_fn_t info,
58 libbpf_print_fn_t debug);
60 /* Hide internal to user */
63 struct bpf_object *bpf_object__open(const char *path);
64 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
67 void bpf_object__close(struct bpf_object *object);
69 /* Load/unload object into/from kernel */
70 int bpf_object__load(struct bpf_object *obj);
71 int bpf_object__unload(struct bpf_object *obj);
72 const char *bpf_object__name(struct bpf_object *obj);
73 unsigned int bpf_object__kversion(struct bpf_object *obj);
75 struct bpf_object *bpf_object__next(struct bpf_object *prev);
76 #define bpf_object__for_each_safe(pos, tmp) \
77 for ((pos) = bpf_object__next(NULL), \
78 (tmp) = bpf_object__next(pos); \
80 (pos) = (tmp), (tmp) = bpf_object__next(tmp))
82 /* Accessors of bpf_program. */
84 struct bpf_program *bpf_program__next(struct bpf_program *prog,
85 struct bpf_object *obj);
87 #define bpf_object__for_each_program(pos, obj) \
88 for ((pos) = bpf_program__next(NULL, (obj)); \
90 (pos) = bpf_program__next((pos), (obj)))
92 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
95 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
96 bpf_program_clear_priv_t clear_priv);
98 void *bpf_program__priv(struct bpf_program *prog);
100 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
102 int bpf_program__fd(struct bpf_program *prog);
107 * Libbpf allows callers to adjust BPF programs before being loaded
108 * into kernel. One program in an object file can be transform into
109 * multiple variants to be attached to different code.
111 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
112 * are APIs for this propose.
114 * - bpf_program_prep_t:
115 * It defines 'preprocessor', which is a caller defined function
116 * passed to libbpf through bpf_program__set_prep(), and will be
117 * called before program is loaded. The processor should adjust
118 * the program one time for each instances according to the number
121 * - bpf_program__set_prep:
122 * Attachs a preprocessor to a BPF program. The number of instances
123 * whould be created is also passed through this function.
125 * - bpf_program__nth_fd:
126 * After the program is loaded, get resuling fds from bpf program for
129 * If bpf_program__set_prep() is not used, the program whould be loaded
130 * without adjustment during bpf_object__load(). The program has only
131 * one instance. In this case bpf_program__fd(prog) is equal to
132 * bpf_program__nth_fd(prog, 0).
135 struct bpf_prog_prep_result {
137 * If not NULL, load new instruction array.
138 * If set to NULL, don't load this instance.
140 struct bpf_insn *new_insn_ptr;
143 /* If not NULL, result fd is set to it */
148 * Parameters of bpf_program_prep_t:
149 * - prog: The bpf_program being loaded.
150 * - n: Index of instance being generated.
151 * - insns: BPF instructions array.
152 * - insns_cnt:Number of instructions in insns.
153 * - res: Output parameter, result of transformation.
156 * - Zero: pre-processing success.
157 * - Non-zero: pre-processing, stop loading.
159 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
160 struct bpf_insn *insns, int insns_cnt,
161 struct bpf_prog_prep_result *res);
163 int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
164 bpf_program_prep_t prep);
166 int bpf_program__nth_fd(struct bpf_program *prog, int n);
169 * Adjust type of bpf program. Default is kprobe.
171 int bpf_program__set_tracepoint(struct bpf_program *prog);
172 int bpf_program__set_kprobe(struct bpf_program *prog);
174 bool bpf_program__is_tracepoint(struct bpf_program *prog);
175 bool bpf_program__is_kprobe(struct bpf_program *prog);
178 * We don't need __attribute__((packed)) now since it is
179 * unnecessary for 'bpf_map_def' because they are all aligned.
180 * In addition, using it will trigger -Wpacked warning message,
181 * and will be treated as an error due to -Werror.
185 unsigned int key_size;
186 unsigned int value_size;
187 unsigned int max_entries;
191 * There is another 'struct bpf_map' in include/linux/map.h. However,
192 * it is not a uapi header so no need to consider name clash.
196 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
199 bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
200 #define bpf_map__for_each(pos, obj) \
201 for ((pos) = bpf_map__next(NULL, (obj)); \
203 (pos) = bpf_map__next((pos), (obj)))
205 int bpf_map__fd(struct bpf_map *map);
206 const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
207 const char *bpf_map__name(struct bpf_map *map);
209 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
210 int bpf_map__set_priv(struct bpf_map *map, void *priv,
211 bpf_map_clear_priv_t clear_priv);
212 void *bpf_map__priv(struct bpf_map *map);