1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 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 #ifndef __LIBBPF_LIBBPF_H 11 #define __LIBBPF_LIBBPF_H 12 13 #include <stdarg.h> 14 #include <stdio.h> 15 #include <stdint.h> 16 #include <stdbool.h> 17 #include <sys/types.h> // for size_t 18 #include <linux/bpf.h> 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 #ifndef LIBBPF_API 25 #define LIBBPF_API __attribute__((visibility("default"))) 26 #endif 27 28 enum libbpf_errno { 29 __LIBBPF_ERRNO__START = 4000, 30 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 */ 43 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 44 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 45 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 46 __LIBBPF_ERRNO__END, 47 }; 48 49 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 50 51 enum libbpf_print_level { 52 LIBBPF_WARN, 53 LIBBPF_INFO, 54 LIBBPF_DEBUG, 55 }; 56 57 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, 58 const char *, va_list ap); 59 60 LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn); 61 62 /* Hide internal to user */ 63 struct bpf_object; 64 65 struct bpf_object_open_attr { 66 const char *file; 67 enum bpf_prog_type prog_type; 68 }; 69 70 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 71 LIBBPF_API struct bpf_object * 72 bpf_object__open_xattr(struct bpf_object_open_attr *attr); 73 struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr, 74 int flags); 75 LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf, 76 size_t obj_buf_sz, 77 const char *name); 78 int bpf_object__section_size(const struct bpf_object *obj, const char *name, 79 __u32 *size); 80 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, 81 __u32 *off); 82 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 83 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 84 const char *path); 85 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 86 const char *path); 87 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 88 const char *path); 89 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 90 LIBBPF_API void bpf_object__close(struct bpf_object *object); 91 92 /* Load/unload object into/from kernel */ 93 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 94 LIBBPF_API int bpf_object__unload(struct bpf_object *obj); 95 LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); 96 LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); 97 98 struct btf; 99 LIBBPF_API struct btf *bpf_object__btf(struct bpf_object *obj); 100 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 101 102 LIBBPF_API struct bpf_program * 103 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); 104 105 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev); 106 #define bpf_object__for_each_safe(pos, tmp) \ 107 for ((pos) = bpf_object__next(NULL), \ 108 (tmp) = bpf_object__next(pos); \ 109 (pos) != NULL; \ 110 (pos) = (tmp), (tmp) = bpf_object__next(tmp)) 111 112 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); 113 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv, 114 bpf_object_clear_priv_t clear_priv); 115 LIBBPF_API void *bpf_object__priv(struct bpf_object *prog); 116 117 LIBBPF_API int 118 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 119 enum bpf_attach_type *expected_attach_type); 120 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 121 enum bpf_attach_type *attach_type); 122 123 /* Accessors of bpf_program */ 124 struct bpf_program; 125 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog, 126 struct bpf_object *obj); 127 128 #define bpf_object__for_each_program(pos, obj) \ 129 for ((pos) = bpf_program__next(NULL, (obj)); \ 130 (pos) != NULL; \ 131 (pos) = bpf_program__next((pos), (obj))) 132 133 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog, 134 struct bpf_object *obj); 135 136 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, 137 void *); 138 139 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv, 140 bpf_program_clear_priv_t clear_priv); 141 142 LIBBPF_API void *bpf_program__priv(struct bpf_program *prog); 143 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 144 __u32 ifindex); 145 146 LIBBPF_API const char *bpf_program__title(struct bpf_program *prog, 147 bool needs_copy); 148 149 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license, 150 __u32 kern_version); 151 LIBBPF_API int bpf_program__fd(struct bpf_program *prog); 152 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog, 153 const char *path, 154 int instance); 155 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog, 156 const char *path, 157 int instance); 158 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 159 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 160 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 161 162 struct bpf_insn; 163 164 /* 165 * Libbpf allows callers to adjust BPF programs before being loaded 166 * into kernel. One program in an object file can be transformed into 167 * multiple variants to be attached to different hooks. 168 * 169 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd 170 * form an API for this purpose. 171 * 172 * - bpf_program_prep_t: 173 * Defines a 'preprocessor', which is a caller defined function 174 * passed to libbpf through bpf_program__set_prep(), and will be 175 * called before program is loaded. The processor should adjust 176 * the program one time for each instance according to the instance id 177 * passed to it. 178 * 179 * - bpf_program__set_prep: 180 * Attaches a preprocessor to a BPF program. The number of instances 181 * that should be created is also passed through this function. 182 * 183 * - bpf_program__nth_fd: 184 * After the program is loaded, get resulting FD of a given instance 185 * of the BPF program. 186 * 187 * If bpf_program__set_prep() is not used, the program would be loaded 188 * without adjustment during bpf_object__load(). The program has only 189 * one instance. In this case bpf_program__fd(prog) is equal to 190 * bpf_program__nth_fd(prog, 0). 191 */ 192 193 struct bpf_prog_prep_result { 194 /* 195 * If not NULL, load new instruction array. 196 * If set to NULL, don't load this instance. 197 */ 198 struct bpf_insn *new_insn_ptr; 199 int new_insn_cnt; 200 201 /* If not NULL, result FD is written to it. */ 202 int *pfd; 203 }; 204 205 /* 206 * Parameters of bpf_program_prep_t: 207 * - prog: The bpf_program being loaded. 208 * - n: Index of instance being generated. 209 * - insns: BPF instructions array. 210 * - insns_cnt:Number of instructions in insns. 211 * - res: Output parameter, result of transformation. 212 * 213 * Return value: 214 * - Zero: pre-processing success. 215 * - Non-zero: pre-processing error, stop loading. 216 */ 217 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, 218 struct bpf_insn *insns, int insns_cnt, 219 struct bpf_prog_prep_result *res); 220 221 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, 222 bpf_program_prep_t prep); 223 224 LIBBPF_API int bpf_program__nth_fd(struct bpf_program *prog, int n); 225 226 /* 227 * Adjust type of BPF program. Default is kprobe. 228 */ 229 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog); 230 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog); 231 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog); 232 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog); 233 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog); 234 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog); 235 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog); 236 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog); 237 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, 238 enum bpf_prog_type type); 239 LIBBPF_API void 240 bpf_program__set_expected_attach_type(struct bpf_program *prog, 241 enum bpf_attach_type type); 242 243 LIBBPF_API bool bpf_program__is_socket_filter(struct bpf_program *prog); 244 LIBBPF_API bool bpf_program__is_tracepoint(struct bpf_program *prog); 245 LIBBPF_API bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); 246 LIBBPF_API bool bpf_program__is_kprobe(struct bpf_program *prog); 247 LIBBPF_API bool bpf_program__is_sched_cls(struct bpf_program *prog); 248 LIBBPF_API bool bpf_program__is_sched_act(struct bpf_program *prog); 249 LIBBPF_API bool bpf_program__is_xdp(struct bpf_program *prog); 250 LIBBPF_API bool bpf_program__is_perf_event(struct bpf_program *prog); 251 252 /* 253 * No need for __attribute__((packed)), all members of 'bpf_map_def' 254 * are all aligned. In addition, using __attribute__((packed)) 255 * would trigger a -Wpacked warning message, and lead to an error 256 * if -Werror is set. 257 */ 258 struct bpf_map_def { 259 unsigned int type; 260 unsigned int key_size; 261 unsigned int value_size; 262 unsigned int max_entries; 263 unsigned int map_flags; 264 }; 265 266 /* 267 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, 268 * so no need to worry about a name clash. 269 */ 270 struct bpf_map; 271 LIBBPF_API struct bpf_map * 272 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); 273 274 LIBBPF_API int 275 bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name); 276 277 /* 278 * Get bpf_map through the offset of corresponding struct bpf_map_def 279 * in the BPF object file. 280 */ 281 LIBBPF_API struct bpf_map * 282 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); 283 284 LIBBPF_API struct bpf_map * 285 bpf_map__next(struct bpf_map *map, struct bpf_object *obj); 286 #define bpf_object__for_each_map(pos, obj) \ 287 for ((pos) = bpf_map__next(NULL, (obj)); \ 288 (pos) != NULL; \ 289 (pos) = bpf_map__next((pos), (obj))) 290 #define bpf_map__for_each bpf_object__for_each_map 291 292 LIBBPF_API struct bpf_map * 293 bpf_map__prev(struct bpf_map *map, struct bpf_object *obj); 294 295 LIBBPF_API int bpf_map__fd(struct bpf_map *map); 296 LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map); 297 LIBBPF_API const char *bpf_map__name(struct bpf_map *map); 298 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 299 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 300 301 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); 302 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, 303 bpf_map_clear_priv_t clear_priv); 304 LIBBPF_API void *bpf_map__priv(struct bpf_map *map); 305 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 306 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries); 307 LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); 308 LIBBPF_API bool bpf_map__is_internal(struct bpf_map *map); 309 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 310 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 311 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 312 313 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 314 315 LIBBPF_API long libbpf_get_error(const void *ptr); 316 317 struct bpf_prog_load_attr { 318 const char *file; 319 enum bpf_prog_type prog_type; 320 enum bpf_attach_type expected_attach_type; 321 int ifindex; 322 int log_level; 323 }; 324 325 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 326 struct bpf_object **pobj, int *prog_fd); 327 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type, 328 struct bpf_object **pobj, int *prog_fd); 329 330 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); 331 LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags); 332 333 enum bpf_perf_event_ret { 334 LIBBPF_PERF_EVENT_DONE = 0, 335 LIBBPF_PERF_EVENT_ERROR = -1, 336 LIBBPF_PERF_EVENT_CONT = -2, 337 }; 338 339 struct perf_event_header; 340 typedef enum bpf_perf_event_ret 341 (*bpf_perf_event_print_t)(struct perf_event_header *hdr, 342 void *private_data); 343 LIBBPF_API enum bpf_perf_event_ret 344 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, 345 void **copy_mem, size_t *copy_size, 346 bpf_perf_event_print_t fn, void *private_data); 347 348 struct nlattr; 349 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 350 int libbpf_netlink_open(unsigned int *nl_pid); 351 int libbpf_nl_get_link(int sock, unsigned int nl_pid, 352 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie); 353 int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex, 354 libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie); 355 int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 356 libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie); 357 int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 358 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie); 359 360 struct bpf_prog_linfo; 361 struct bpf_prog_info; 362 363 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 364 LIBBPF_API struct bpf_prog_linfo * 365 bpf_prog_linfo__new(const struct bpf_prog_info *info); 366 LIBBPF_API const struct bpf_line_info * 367 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 368 __u64 addr, __u32 func_idx, __u32 nr_skip); 369 LIBBPF_API const struct bpf_line_info * 370 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 371 __u32 insn_off, __u32 nr_skip); 372 373 /* 374 * Probe for supported system features 375 * 376 * Note that running many of these probes in a short amount of time can cause 377 * the kernel to reach the maximal size of lockable memory allowed for the 378 * user, causing subsequent probes to fail. In this case, the caller may want 379 * to adjust that limit with setrlimit(). 380 */ 381 LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type, 382 __u32 ifindex); 383 LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex); 384 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id, 385 enum bpf_prog_type prog_type, __u32 ifindex); 386 387 /* 388 * Get bpf_prog_info in continuous memory 389 * 390 * struct bpf_prog_info has multiple arrays. The user has option to choose 391 * arrays to fetch from kernel. The following APIs provide an uniform way to 392 * fetch these data. All arrays in bpf_prog_info are stored in a single 393 * continuous memory region. This makes it easy to store the info in a 394 * file. 395 * 396 * Before writing bpf_prog_info_linear to files, it is necessary to 397 * translate pointers in bpf_prog_info to offsets. Helper functions 398 * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr() 399 * are introduced to switch between pointers and offsets. 400 * 401 * Examples: 402 * # To fetch map_ids and prog_tags: 403 * __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) | 404 * (1UL << BPF_PROG_INFO_PROG_TAGS); 405 * struct bpf_prog_info_linear *info_linear = 406 * bpf_program__get_prog_info_linear(fd, arrays); 407 * 408 * # To save data in file 409 * bpf_program__bpil_addr_to_offs(info_linear); 410 * write(f, info_linear, sizeof(*info_linear) + info_linear->data_len); 411 * 412 * # To read data from file 413 * read(f, info_linear, <proper_size>); 414 * bpf_program__bpil_offs_to_addr(info_linear); 415 */ 416 enum bpf_prog_info_array { 417 BPF_PROG_INFO_FIRST_ARRAY = 0, 418 BPF_PROG_INFO_JITED_INSNS = 0, 419 BPF_PROG_INFO_XLATED_INSNS, 420 BPF_PROG_INFO_MAP_IDS, 421 BPF_PROG_INFO_JITED_KSYMS, 422 BPF_PROG_INFO_JITED_FUNC_LENS, 423 BPF_PROG_INFO_FUNC_INFO, 424 BPF_PROG_INFO_LINE_INFO, 425 BPF_PROG_INFO_JITED_LINE_INFO, 426 BPF_PROG_INFO_PROG_TAGS, 427 BPF_PROG_INFO_LAST_ARRAY, 428 }; 429 430 struct bpf_prog_info_linear { 431 /* size of struct bpf_prog_info, when the tool is compiled */ 432 __u32 info_len; 433 /* total bytes allocated for data, round up to 8 bytes */ 434 __u32 data_len; 435 /* which arrays are included in data */ 436 __u64 arrays; 437 struct bpf_prog_info info; 438 __u8 data[]; 439 }; 440 441 LIBBPF_API struct bpf_prog_info_linear * 442 bpf_program__get_prog_info_linear(int fd, __u64 arrays); 443 444 LIBBPF_API void 445 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear); 446 447 LIBBPF_API void 448 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear); 449 450 #ifdef __cplusplus 451 } /* extern "C" */ 452 #endif 453 454 #endif /* __LIBBPF_LIBBPF_H */ 455