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 32 enum 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 52 int libbpf_strerror(int err, char *buf, size_t size); 53 54 /* 55 * __printf is defined in include/linux/compiler-gcc.h. However, 56 * it would be better if libbpf.h didn't depend on Linux header files. 57 * So instead of __printf, here we use gcc attribute directly. 58 */ 59 typedef int (*libbpf_print_fn_t)(const char *, ...) 60 __attribute__((format(printf, 1, 2))); 61 62 void 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 */ 67 struct bpf_object; 68 69 struct bpf_object_open_attr { 70 const char *file; 71 enum bpf_prog_type prog_type; 72 }; 73 74 struct bpf_object *bpf_object__open(const char *path); 75 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr); 76 struct bpf_object *bpf_object__open_buffer(void *obj_buf, 77 size_t obj_buf_sz, 78 const char *name); 79 int bpf_object__pin(struct bpf_object *object, const char *path); 80 void bpf_object__close(struct bpf_object *object); 81 82 /* Load/unload object into/from kernel */ 83 int bpf_object__load(struct bpf_object *obj); 84 int bpf_object__unload(struct bpf_object *obj); 85 const char *bpf_object__name(struct bpf_object *obj); 86 unsigned int bpf_object__kversion(struct bpf_object *obj); 87 int bpf_object__btf_fd(const struct bpf_object *obj); 88 89 struct bpf_program * 90 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); 91 92 struct bpf_object *bpf_object__next(struct bpf_object *prev); 93 #define bpf_object__for_each_safe(pos, tmp) \ 94 for ((pos) = bpf_object__next(NULL), \ 95 (tmp) = bpf_object__next(pos); \ 96 (pos) != NULL; \ 97 (pos) = (tmp), (tmp) = bpf_object__next(tmp)) 98 99 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); 100 int bpf_object__set_priv(struct bpf_object *obj, void *priv, 101 bpf_object_clear_priv_t clear_priv); 102 void *bpf_object__priv(struct bpf_object *prog); 103 104 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 105 enum bpf_attach_type *expected_attach_type); 106 107 /* Accessors of bpf_program */ 108 struct bpf_program; 109 struct bpf_program *bpf_program__next(struct bpf_program *prog, 110 struct bpf_object *obj); 111 112 #define bpf_object__for_each_program(pos, obj) \ 113 for ((pos) = bpf_program__next(NULL, (obj)); \ 114 (pos) != NULL; \ 115 (pos) = bpf_program__next((pos), (obj))) 116 117 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, 118 void *); 119 120 int bpf_program__set_priv(struct bpf_program *prog, void *priv, 121 bpf_program_clear_priv_t clear_priv); 122 123 void *bpf_program__priv(struct bpf_program *prog); 124 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex); 125 126 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); 127 128 int bpf_program__fd(struct bpf_program *prog); 129 int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 130 int instance); 131 int bpf_program__pin(struct bpf_program *prog, const char *path); 132 133 struct bpf_insn; 134 135 /* 136 * Libbpf allows callers to adjust BPF programs before being loaded 137 * into kernel. One program in an object file can be transformed into 138 * multiple variants to be attached to different hooks. 139 * 140 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd 141 * form an API for this purpose. 142 * 143 * - bpf_program_prep_t: 144 * Defines a 'preprocessor', which is a caller defined function 145 * passed to libbpf through bpf_program__set_prep(), and will be 146 * called before program is loaded. The processor should adjust 147 * the program one time for each instance according to the instance id 148 * passed to it. 149 * 150 * - bpf_program__set_prep: 151 * Attaches a preprocessor to a BPF program. The number of instances 152 * that should be created is also passed through this function. 153 * 154 * - bpf_program__nth_fd: 155 * After the program is loaded, get resulting FD of a given instance 156 * of the BPF program. 157 * 158 * If bpf_program__set_prep() is not used, the program would be loaded 159 * without adjustment during bpf_object__load(). The program has only 160 * one instance. In this case bpf_program__fd(prog) is equal to 161 * bpf_program__nth_fd(prog, 0). 162 */ 163 164 struct bpf_prog_prep_result { 165 /* 166 * If not NULL, load new instruction array. 167 * If set to NULL, don't load this instance. 168 */ 169 struct bpf_insn *new_insn_ptr; 170 int new_insn_cnt; 171 172 /* If not NULL, result FD is written to it. */ 173 int *pfd; 174 }; 175 176 /* 177 * Parameters of bpf_program_prep_t: 178 * - prog: The bpf_program being loaded. 179 * - n: Index of instance being generated. 180 * - insns: BPF instructions array. 181 * - insns_cnt:Number of instructions in insns. 182 * - res: Output parameter, result of transformation. 183 * 184 * Return value: 185 * - Zero: pre-processing success. 186 * - Non-zero: pre-processing error, stop loading. 187 */ 188 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, 189 struct bpf_insn *insns, int insns_cnt, 190 struct bpf_prog_prep_result *res); 191 192 int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, 193 bpf_program_prep_t prep); 194 195 int bpf_program__nth_fd(struct bpf_program *prog, int n); 196 197 /* 198 * Adjust type of BPF program. Default is kprobe. 199 */ 200 int bpf_program__set_socket_filter(struct bpf_program *prog); 201 int bpf_program__set_tracepoint(struct bpf_program *prog); 202 int bpf_program__set_raw_tracepoint(struct bpf_program *prog); 203 int bpf_program__set_kprobe(struct bpf_program *prog); 204 int bpf_program__set_sched_cls(struct bpf_program *prog); 205 int bpf_program__set_sched_act(struct bpf_program *prog); 206 int bpf_program__set_xdp(struct bpf_program *prog); 207 int bpf_program__set_perf_event(struct bpf_program *prog); 208 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type); 209 void bpf_program__set_expected_attach_type(struct bpf_program *prog, 210 enum bpf_attach_type type); 211 212 bool bpf_program__is_socket_filter(struct bpf_program *prog); 213 bool bpf_program__is_tracepoint(struct bpf_program *prog); 214 bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); 215 bool bpf_program__is_kprobe(struct bpf_program *prog); 216 bool bpf_program__is_sched_cls(struct bpf_program *prog); 217 bool bpf_program__is_sched_act(struct bpf_program *prog); 218 bool bpf_program__is_xdp(struct bpf_program *prog); 219 bool bpf_program__is_perf_event(struct bpf_program *prog); 220 221 /* 222 * No need for __attribute__((packed)), all members of 'bpf_map_def' 223 * are all aligned. In addition, using __attribute__((packed)) 224 * would trigger a -Wpacked warning message, and lead to an error 225 * if -Werror is set. 226 */ 227 struct bpf_map_def { 228 unsigned int type; 229 unsigned int key_size; 230 unsigned int value_size; 231 unsigned int max_entries; 232 unsigned int map_flags; 233 }; 234 235 /* 236 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, 237 * so no need to worry about a name clash. 238 */ 239 struct bpf_map; 240 struct bpf_map * 241 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); 242 243 /* 244 * Get bpf_map through the offset of corresponding struct bpf_map_def 245 * in the BPF object file. 246 */ 247 struct bpf_map * 248 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); 249 250 struct bpf_map * 251 bpf_map__next(struct bpf_map *map, struct bpf_object *obj); 252 #define bpf_map__for_each(pos, obj) \ 253 for ((pos) = bpf_map__next(NULL, (obj)); \ 254 (pos) != NULL; \ 255 (pos) = bpf_map__next((pos), (obj))) 256 257 int bpf_map__fd(struct bpf_map *map); 258 const struct bpf_map_def *bpf_map__def(struct bpf_map *map); 259 const char *bpf_map__name(struct bpf_map *map); 260 __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 261 __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 262 263 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); 264 int bpf_map__set_priv(struct bpf_map *map, void *priv, 265 bpf_map_clear_priv_t clear_priv); 266 void *bpf_map__priv(struct bpf_map *map); 267 int bpf_map__reuse_fd(struct bpf_map *map, int fd); 268 bool bpf_map__is_offload_neutral(struct bpf_map *map); 269 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 270 int bpf_map__pin(struct bpf_map *map, const char *path); 271 272 long libbpf_get_error(const void *ptr); 273 274 struct bpf_prog_load_attr { 275 const char *file; 276 enum bpf_prog_type prog_type; 277 enum bpf_attach_type expected_attach_type; 278 int ifindex; 279 }; 280 281 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 282 struct bpf_object **pobj, int *prog_fd); 283 int bpf_prog_load(const char *file, enum bpf_prog_type type, 284 struct bpf_object **pobj, int *prog_fd); 285 286 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); 287 288 enum bpf_perf_event_ret { 289 LIBBPF_PERF_EVENT_DONE = 0, 290 LIBBPF_PERF_EVENT_ERROR = -1, 291 LIBBPF_PERF_EVENT_CONT = -2, 292 }; 293 294 typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, 295 void *priv); 296 int bpf_perf_event_read_simple(void *mem, unsigned long size, 297 unsigned long page_size, 298 void **buf, size_t *buf_len, 299 bpf_perf_event_print_t fn, void *priv); 300 #endif 301