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 <stdio.h> 14 #include <stdint.h> 15 #include <stdbool.h> 16 #include <sys/types.h> // for size_t 17 #include <linux/bpf.h> 18 19 #ifdef __cplusplus 20 extern "C" { 21 #endif 22 23 #ifndef LIBBPF_API 24 #define LIBBPF_API __attribute__((visibility("default"))) 25 #endif 26 27 enum libbpf_errno { 28 __LIBBPF_ERRNO__START = 4000, 29 30 /* Something wrong in libelf */ 31 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 32 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 33 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 34 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 35 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 36 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 37 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 38 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 39 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 40 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 41 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 42 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 43 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 44 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 45 __LIBBPF_ERRNO__END, 46 }; 47 48 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 49 50 /* 51 * __printf is defined in include/linux/compiler-gcc.h. However, 52 * it would be better if libbpf.h didn't depend on Linux header files. 53 * So instead of __printf, here we use gcc attribute directly. 54 */ 55 typedef int (*libbpf_print_fn_t)(const char *, ...) 56 __attribute__((format(printf, 1, 2))); 57 58 LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn, 59 libbpf_print_fn_t info, 60 libbpf_print_fn_t debug); 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 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 79 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 80 const char *path); 81 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 82 const char *path); 83 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 84 const char *path); 85 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 86 LIBBPF_API void bpf_object__close(struct bpf_object *object); 87 88 /* Load/unload object into/from kernel */ 89 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 90 LIBBPF_API int bpf_object__unload(struct bpf_object *obj); 91 LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); 92 LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); 93 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 94 95 LIBBPF_API struct bpf_program * 96 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); 97 98 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev); 99 #define bpf_object__for_each_safe(pos, tmp) \ 100 for ((pos) = bpf_object__next(NULL), \ 101 (tmp) = bpf_object__next(pos); \ 102 (pos) != NULL; \ 103 (pos) = (tmp), (tmp) = bpf_object__next(tmp)) 104 105 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); 106 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv, 107 bpf_object_clear_priv_t clear_priv); 108 LIBBPF_API void *bpf_object__priv(struct bpf_object *prog); 109 110 LIBBPF_API int 111 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 112 enum bpf_attach_type *expected_attach_type); 113 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 114 enum bpf_attach_type *attach_type); 115 116 /* Accessors of bpf_program */ 117 struct bpf_program; 118 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog, 119 struct bpf_object *obj); 120 121 #define bpf_object__for_each_program(pos, obj) \ 122 for ((pos) = bpf_program__next(NULL, (obj)); \ 123 (pos) != NULL; \ 124 (pos) = bpf_program__next((pos), (obj))) 125 126 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog, 127 struct bpf_object *obj); 128 129 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, 130 void *); 131 132 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv, 133 bpf_program_clear_priv_t clear_priv); 134 135 LIBBPF_API void *bpf_program__priv(struct bpf_program *prog); 136 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 137 __u32 ifindex); 138 139 LIBBPF_API const char *bpf_program__title(struct bpf_program *prog, 140 bool needs_copy); 141 142 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license, 143 __u32 kern_version); 144 LIBBPF_API int bpf_program__fd(struct bpf_program *prog); 145 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog, 146 const char *path, 147 int instance); 148 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog, 149 const char *path, 150 int instance); 151 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 152 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 153 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 154 155 struct bpf_insn; 156 157 /* 158 * Libbpf allows callers to adjust BPF programs before being loaded 159 * into kernel. One program in an object file can be transformed into 160 * multiple variants to be attached to different hooks. 161 * 162 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd 163 * form an API for this purpose. 164 * 165 * - bpf_program_prep_t: 166 * Defines a 'preprocessor', which is a caller defined function 167 * passed to libbpf through bpf_program__set_prep(), and will be 168 * called before program is loaded. The processor should adjust 169 * the program one time for each instance according to the instance id 170 * passed to it. 171 * 172 * - bpf_program__set_prep: 173 * Attaches a preprocessor to a BPF program. The number of instances 174 * that should be created is also passed through this function. 175 * 176 * - bpf_program__nth_fd: 177 * After the program is loaded, get resulting FD of a given instance 178 * of the BPF program. 179 * 180 * If bpf_program__set_prep() is not used, the program would be loaded 181 * without adjustment during bpf_object__load(). The program has only 182 * one instance. In this case bpf_program__fd(prog) is equal to 183 * bpf_program__nth_fd(prog, 0). 184 */ 185 186 struct bpf_prog_prep_result { 187 /* 188 * If not NULL, load new instruction array. 189 * If set to NULL, don't load this instance. 190 */ 191 struct bpf_insn *new_insn_ptr; 192 int new_insn_cnt; 193 194 /* If not NULL, result FD is written to it. */ 195 int *pfd; 196 }; 197 198 /* 199 * Parameters of bpf_program_prep_t: 200 * - prog: The bpf_program being loaded. 201 * - n: Index of instance being generated. 202 * - insns: BPF instructions array. 203 * - insns_cnt:Number of instructions in insns. 204 * - res: Output parameter, result of transformation. 205 * 206 * Return value: 207 * - Zero: pre-processing success. 208 * - Non-zero: pre-processing error, stop loading. 209 */ 210 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, 211 struct bpf_insn *insns, int insns_cnt, 212 struct bpf_prog_prep_result *res); 213 214 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, 215 bpf_program_prep_t prep); 216 217 LIBBPF_API int bpf_program__nth_fd(struct bpf_program *prog, int n); 218 219 /* 220 * Adjust type of BPF program. Default is kprobe. 221 */ 222 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog); 223 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog); 224 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog); 225 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog); 226 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog); 227 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog); 228 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog); 229 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog); 230 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, 231 enum bpf_prog_type type); 232 LIBBPF_API void 233 bpf_program__set_expected_attach_type(struct bpf_program *prog, 234 enum bpf_attach_type type); 235 236 LIBBPF_API bool bpf_program__is_socket_filter(struct bpf_program *prog); 237 LIBBPF_API bool bpf_program__is_tracepoint(struct bpf_program *prog); 238 LIBBPF_API bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); 239 LIBBPF_API bool bpf_program__is_kprobe(struct bpf_program *prog); 240 LIBBPF_API bool bpf_program__is_sched_cls(struct bpf_program *prog); 241 LIBBPF_API bool bpf_program__is_sched_act(struct bpf_program *prog); 242 LIBBPF_API bool bpf_program__is_xdp(struct bpf_program *prog); 243 LIBBPF_API bool bpf_program__is_perf_event(struct bpf_program *prog); 244 245 /* 246 * No need for __attribute__((packed)), all members of 'bpf_map_def' 247 * are all aligned. In addition, using __attribute__((packed)) 248 * would trigger a -Wpacked warning message, and lead to an error 249 * if -Werror is set. 250 */ 251 struct bpf_map_def { 252 unsigned int type; 253 unsigned int key_size; 254 unsigned int value_size; 255 unsigned int max_entries; 256 unsigned int map_flags; 257 }; 258 259 /* 260 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, 261 * so no need to worry about a name clash. 262 */ 263 struct bpf_map; 264 LIBBPF_API struct bpf_map * 265 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); 266 267 /* 268 * Get bpf_map through the offset of corresponding struct bpf_map_def 269 * in the BPF object file. 270 */ 271 LIBBPF_API struct bpf_map * 272 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); 273 274 LIBBPF_API struct bpf_map * 275 bpf_map__next(struct bpf_map *map, struct bpf_object *obj); 276 #define bpf_map__for_each(pos, obj) \ 277 for ((pos) = bpf_map__next(NULL, (obj)); \ 278 (pos) != NULL; \ 279 (pos) = bpf_map__next((pos), (obj))) 280 281 LIBBPF_API struct bpf_map * 282 bpf_map__prev(struct bpf_map *map, struct bpf_object *obj); 283 284 LIBBPF_API int bpf_map__fd(struct bpf_map *map); 285 LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map); 286 LIBBPF_API const char *bpf_map__name(struct bpf_map *map); 287 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 288 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 289 290 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); 291 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, 292 bpf_map_clear_priv_t clear_priv); 293 LIBBPF_API void *bpf_map__priv(struct bpf_map *map); 294 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 295 LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); 296 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 297 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 298 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 299 300 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 301 302 LIBBPF_API long libbpf_get_error(const void *ptr); 303 304 struct bpf_prog_load_attr { 305 const char *file; 306 enum bpf_prog_type prog_type; 307 enum bpf_attach_type expected_attach_type; 308 int ifindex; 309 }; 310 311 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 312 struct bpf_object **pobj, int *prog_fd); 313 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type, 314 struct bpf_object **pobj, int *prog_fd); 315 316 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); 317 318 enum bpf_perf_event_ret { 319 LIBBPF_PERF_EVENT_DONE = 0, 320 LIBBPF_PERF_EVENT_ERROR = -1, 321 LIBBPF_PERF_EVENT_CONT = -2, 322 }; 323 324 struct perf_event_header; 325 typedef enum bpf_perf_event_ret 326 (*bpf_perf_event_print_t)(struct perf_event_header *hdr, 327 void *private_data); 328 LIBBPF_API enum bpf_perf_event_ret 329 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, 330 void **copy_mem, size_t *copy_size, 331 bpf_perf_event_print_t fn, void *private_data); 332 333 struct nlattr; 334 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 335 int libbpf_netlink_open(unsigned int *nl_pid); 336 int libbpf_nl_get_link(int sock, unsigned int nl_pid, 337 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie); 338 int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex, 339 libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie); 340 int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 341 libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie); 342 int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 343 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie); 344 345 struct bpf_prog_linfo; 346 struct bpf_prog_info; 347 348 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 349 LIBBPF_API struct bpf_prog_linfo * 350 bpf_prog_linfo__new(const struct bpf_prog_info *info); 351 LIBBPF_API const struct bpf_line_info * 352 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 353 __u64 addr, __u32 func_idx, __u32 nr_skip); 354 LIBBPF_API const struct bpf_line_info * 355 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 356 __u32 insn_off, __u32 nr_skip); 357 358 #ifdef __cplusplus 359 } /* extern "C" */ 360 #endif 361 362 #endif /* __LIBBPF_LIBBPF_H */ 363