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 #include "libbpf_common.h" 21 #include "libbpf_legacy.h" 22 23 #ifdef __cplusplus 24 extern "C" { 25 #endif 26 27 LIBBPF_API __u32 libbpf_major_version(void); 28 LIBBPF_API __u32 libbpf_minor_version(void); 29 LIBBPF_API const char *libbpf_version_string(void); 30 31 enum libbpf_errno { 32 __LIBBPF_ERRNO__START = 4000, 33 34 /* Something wrong in libelf */ 35 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 36 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 37 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 38 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 39 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 40 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 41 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 42 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 43 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 44 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 45 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 46 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 47 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 48 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 49 __LIBBPF_ERRNO__END, 50 }; 51 52 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 53 54 /** 55 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type 56 * value into a textual representation. 57 * @param t The attach type. 58 * @return Pointer to a static string identifying the attach type. NULL is 59 * returned for unknown **bpf_attach_type** values. 60 */ 61 LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t); 62 63 /** 64 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value 65 * into a textual representation. 66 * @param t The link type. 67 * @return Pointer to a static string identifying the link type. NULL is 68 * returned for unknown **bpf_link_type** values. 69 */ 70 LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t); 71 72 /** 73 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value 74 * into a textual representation. 75 * @param t The map type. 76 * @return Pointer to a static string identifying the map type. NULL is 77 * returned for unknown **bpf_map_type** values. 78 */ 79 LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t); 80 81 /** 82 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type 83 * value into a textual representation. 84 * @param t The program type. 85 * @return Pointer to a static string identifying the program type. NULL is 86 * returned for unknown **bpf_prog_type** values. 87 */ 88 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t); 89 90 enum libbpf_print_level { 91 LIBBPF_WARN, 92 LIBBPF_INFO, 93 LIBBPF_DEBUG, 94 }; 95 96 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, 97 const char *, va_list ap); 98 99 /** 100 * @brief **libbpf_set_print()** sets user-provided log callback function to 101 * be used for libbpf warnings and informational messages. 102 * @param fn The log print function. If NULL, libbpf won't print anything. 103 * @return Pointer to old print function. 104 * 105 * This function is thread-safe. 106 */ 107 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); 108 109 /* Hide internal to user */ 110 struct bpf_object; 111 112 struct bpf_object_open_opts { 113 /* size of this struct, for forward/backward compatibility */ 114 size_t sz; 115 /* object name override, if provided: 116 * - for object open from file, this will override setting object 117 * name from file path's base name; 118 * - for object open from memory buffer, this will specify an object 119 * name and will override default "<addr>-<buf-size>" name; 120 */ 121 const char *object_name; 122 /* parse map definitions non-strictly, allowing extra attributes/data */ 123 bool relaxed_maps; 124 /* maps that set the 'pinning' attribute in their definition will have 125 * their pin_path attribute set to a file in this directory, and be 126 * auto-pinned to that path on load; defaults to "/sys/fs/bpf". 127 */ 128 const char *pin_root_path; 129 130 __u32 :32; /* stub out now removed attach_prog_fd */ 131 132 /* Additional kernel config content that augments and overrides 133 * system Kconfig for CONFIG_xxx externs. 134 */ 135 const char *kconfig; 136 /* Path to the custom BTF to be used for BPF CO-RE relocations. 137 * This custom BTF completely replaces the use of vmlinux BTF 138 * for the purpose of CO-RE relocations. 139 * NOTE: any other BPF feature (e.g., fentry/fexit programs, 140 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. 141 */ 142 const char *btf_custom_path; 143 /* Pointer to a buffer for storing kernel logs for applicable BPF 144 * commands. Valid kernel_log_size has to be specified as well and are 145 * passed-through to bpf() syscall. Keep in mind that kernel might 146 * fail operation with -ENOSPC error if provided buffer is too small 147 * to contain entire log output. 148 * See the comment below for kernel_log_level for interaction between 149 * log_buf and log_level settings. 150 * 151 * If specified, this log buffer will be passed for: 152 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden 153 * with bpf_program__set_log() on per-program level, to get 154 * BPF verifier log output. 155 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get 156 * BTF sanity checking log. 157 * 158 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite 159 * previous contents, so if you need more fine-grained control, set 160 * per-program buffer with bpf_program__set_log_buf() to preserve each 161 * individual program's verification log. Keep using kernel_log_buf 162 * for BTF verification log, if necessary. 163 */ 164 char *kernel_log_buf; 165 size_t kernel_log_size; 166 /* 167 * Log level can be set independently from log buffer. Log_level=0 168 * means that libbpf will attempt loading BTF or program without any 169 * logging requested, but will retry with either its own or custom log 170 * buffer, if provided, and log_level=1 on any error. 171 * And vice versa, setting log_level>0 will request BTF or prog 172 * loading with verbose log from the first attempt (and as such also 173 * for successfully loaded BTF or program), and the actual log buffer 174 * could be either libbpf's own auto-allocated log buffer, if 175 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. 176 * If user didn't provide custom log buffer, libbpf will emit captured 177 * logs through its print callback. 178 */ 179 __u32 kernel_log_level; 180 181 size_t :0; 182 }; 183 #define bpf_object_open_opts__last_field kernel_log_level 184 185 /** 186 * @brief **bpf_object__open()** creates a bpf_object by opening 187 * the BPF ELF object file pointed to by the passed path and loading it 188 * into memory. 189 * @param path BPF object file path. 190 * @return pointer to the new bpf_object; or NULL is returned on error, 191 * error code is stored in errno 192 */ 193 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 194 195 /** 196 * @brief **bpf_object__open_file()** creates a bpf_object by opening 197 * the BPF ELF object file pointed to by the passed path and loading it 198 * into memory. 199 * @param path BPF object file path 200 * @param opts options for how to load the bpf object, this parameter is 201 * optional and can be set to NULL 202 * @return pointer to the new bpf_object; or NULL is returned on error, 203 * error code is stored in errno 204 */ 205 LIBBPF_API struct bpf_object * 206 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); 207 208 /** 209 * @brief **bpf_object__open_mem()** creates a bpf_object by reading 210 * the BPF objects raw bytes from a memory buffer containing a valid 211 * BPF ELF object file. 212 * @param obj_buf pointer to the buffer containing ELF file bytes 213 * @param obj_buf_sz number of bytes in the buffer 214 * @param opts options for how to load the bpf object 215 * @return pointer to the new bpf_object; or NULL is returned on error, 216 * error code is stored in errno 217 */ 218 LIBBPF_API struct bpf_object * 219 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, 220 const struct bpf_object_open_opts *opts); 221 222 /** 223 * @brief **bpf_object__load()** loads BPF object into kernel. 224 * @param obj Pointer to a valid BPF object instance returned by 225 * **bpf_object__open*()** APIs 226 * @return 0, on success; negative error code, otherwise, error code is 227 * stored in errno 228 */ 229 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 230 231 /** 232 * @brief **bpf_object__close()** closes a BPF object and releases all 233 * resources. 234 * @param obj Pointer to a valid BPF object 235 */ 236 LIBBPF_API void bpf_object__close(struct bpf_object *obj); 237 238 /** 239 * @brief **bpf_object__pin_maps()** pins each map contained within 240 * the BPF object at the passed directory. 241 * @param obj Pointer to a valid BPF object 242 * @param path A directory where maps should be pinned. 243 * @return 0, on success; negative error code, otherwise 244 * 245 * If `path` is NULL `bpf_map__pin` (which is being used on each map) 246 * will use the pin_path attribute of each map. In this case, maps that 247 * don't have a pin_path set will be ignored. 248 */ 249 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 250 251 /** 252 * @brief **bpf_object__unpin_maps()** unpins each map contained within 253 * the BPF object found in the passed directory. 254 * @param obj Pointer to a valid BPF object 255 * @param path A directory where pinned maps should be searched for. 256 * @return 0, on success; negative error code, otherwise 257 * 258 * If `path` is NULL `bpf_map__unpin` (which is being used on each map) 259 * will use the pin_path attribute of each map. In this case, maps that 260 * don't have a pin_path set will be ignored. 261 */ 262 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 263 const char *path); 264 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 265 const char *path); 266 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 267 const char *path); 268 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 269 270 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); 271 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); 272 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); 273 274 struct btf; 275 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); 276 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 277 278 LIBBPF_API struct bpf_program * 279 bpf_object__find_program_by_name(const struct bpf_object *obj, 280 const char *name); 281 282 LIBBPF_API int 283 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 284 enum bpf_attach_type *expected_attach_type); 285 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 286 enum bpf_attach_type *attach_type); 287 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, 288 enum bpf_attach_type attach_type); 289 290 /* Accessors of bpf_program */ 291 struct bpf_program; 292 293 LIBBPF_API struct bpf_program * 294 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); 295 296 #define bpf_object__for_each_program(pos, obj) \ 297 for ((pos) = bpf_object__next_program((obj), NULL); \ 298 (pos) != NULL; \ 299 (pos) = bpf_object__next_program((obj), (pos))) 300 301 LIBBPF_API struct bpf_program * 302 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); 303 304 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 305 __u32 ifindex); 306 307 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); 308 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); 309 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); 310 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); 311 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog); 312 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach); 313 314 struct bpf_insn; 315 316 /** 317 * @brief **bpf_program__insns()** gives read-only access to BPF program's 318 * underlying BPF instructions. 319 * @param prog BPF program for which to return instructions 320 * @return a pointer to an array of BPF instructions that belong to the 321 * specified BPF program 322 * 323 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` 324 * pointed to can be fetched using **bpf_program__insn_cnt()** API. 325 * 326 * Keep in mind, libbpf can modify and append/delete BPF program's 327 * instructions as it processes BPF object file and prepares everything for 328 * uploading into the kernel. So depending on the point in BPF object 329 * lifetime, **bpf_program__insns()** can return different sets of 330 * instructions. As an example, during BPF object load phase BPF program 331 * instructions will be CO-RE-relocated, BPF subprograms instructions will be 332 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions 333 * returned before **bpf_object__load()** and after it might be quite 334 * different. 335 */ 336 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); 337 338 /** 339 * @brief **bpf_program__set_insns()** can set BPF program's underlying 340 * BPF instructions. 341 * 342 * WARNING: This is a very advanced libbpf API and users need to know 343 * what they are doing. This should be used from prog_prepare_load_fn 344 * callback only. 345 * 346 * @param prog BPF program for which to return instructions 347 * @param new_insns a pointer to an array of BPF instructions 348 * @param new_insn_cnt number of `struct bpf_insn`'s that form 349 * specified BPF program 350 * @return 0, on success; negative error code, otherwise 351 */ 352 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, 353 struct bpf_insn *new_insns, size_t new_insn_cnt); 354 355 /** 356 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s 357 * that form specified BPF program. 358 * @param prog BPF program for which to return number of BPF instructions 359 * 360 * See **bpf_program__insns()** documentation for notes on how libbpf can 361 * change instructions and their count during different phases of 362 * **bpf_object** lifetime. 363 */ 364 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); 365 366 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); 367 368 /** 369 * @brief **bpf_program__pin()** pins the BPF program to a file 370 * in the BPF FS specified by a path. This increments the programs 371 * reference count, allowing it to stay loaded after the process 372 * which loaded it has exited. 373 * 374 * @param prog BPF program to pin, must already be loaded 375 * @param path file path in a BPF file system 376 * @return 0, on success; negative error code, otherwise 377 */ 378 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 379 380 /** 381 * @brief **bpf_program__unpin()** unpins the BPF program from a file 382 * in the BPFFS specified by a path. This decrements the programs 383 * reference count. 384 * 385 * The file pinning the BPF program can also be unlinked by a different 386 * process in which case this function will return an error. 387 * 388 * @param prog BPF program to unpin 389 * @param path file path to the pin in a BPF file system 390 * @return 0, on success; negative error code, otherwise 391 */ 392 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 393 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 394 395 struct bpf_link; 396 397 LIBBPF_API struct bpf_link *bpf_link__open(const char *path); 398 LIBBPF_API int bpf_link__fd(const struct bpf_link *link); 399 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); 400 /** 401 * @brief **bpf_link__pin()** pins the BPF link to a file 402 * in the BPF FS specified by a path. This increments the links 403 * reference count, allowing it to stay loaded after the process 404 * which loaded it has exited. 405 * 406 * @param link BPF link to pin, must already be loaded 407 * @param path file path in a BPF file system 408 * @return 0, on success; negative error code, otherwise 409 */ 410 411 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); 412 413 /** 414 * @brief **bpf_link__unpin()** unpins the BPF link from a file 415 * in the BPFFS specified by a path. This decrements the links 416 * reference count. 417 * 418 * The file pinning the BPF link can also be unlinked by a different 419 * process in which case this function will return an error. 420 * 421 * @param prog BPF program to unpin 422 * @param path file path to the pin in a BPF file system 423 * @return 0, on success; negative error code, otherwise 424 */ 425 LIBBPF_API int bpf_link__unpin(struct bpf_link *link); 426 LIBBPF_API int bpf_link__update_program(struct bpf_link *link, 427 struct bpf_program *prog); 428 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); 429 LIBBPF_API int bpf_link__detach(struct bpf_link *link); 430 LIBBPF_API int bpf_link__destroy(struct bpf_link *link); 431 432 /** 433 * @brief **bpf_program__attach()** is a generic function for attaching 434 * a BPF program based on auto-detection of program type, attach type, 435 * and extra paremeters, where applicable. 436 * 437 * @param prog BPF program to attach 438 * @return Reference to the newly created BPF link; or NULL is returned on error, 439 * error code is stored in errno 440 * 441 * This is supported for: 442 * - kprobe/kretprobe (depends on SEC() definition) 443 * - uprobe/uretprobe (depends on SEC() definition) 444 * - tracepoint 445 * - raw tracepoint 446 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) 447 */ 448 LIBBPF_API struct bpf_link * 449 bpf_program__attach(const struct bpf_program *prog); 450 451 struct bpf_perf_event_opts { 452 /* size of this struct, for forward/backward compatibility */ 453 size_t sz; 454 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 455 __u64 bpf_cookie; 456 /* don't use BPF link when attach BPF program */ 457 bool force_ioctl_attach; 458 size_t :0; 459 }; 460 #define bpf_perf_event_opts__last_field force_ioctl_attach 461 462 LIBBPF_API struct bpf_link * 463 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); 464 465 LIBBPF_API struct bpf_link * 466 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, 467 const struct bpf_perf_event_opts *opts); 468 469 /** 470 * enum probe_attach_mode - the mode to attach kprobe/uprobe 471 * 472 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will 473 * be returned if it is not supported by the kernel. 474 */ 475 enum probe_attach_mode { 476 /* attach probe in latest supported mode by kernel */ 477 PROBE_ATTACH_MODE_DEFAULT = 0, 478 /* attach probe in legacy mode, using debugfs/tracefs */ 479 PROBE_ATTACH_MODE_LEGACY, 480 /* create perf event with perf_event_open() syscall */ 481 PROBE_ATTACH_MODE_PERF, 482 /* attach probe with BPF link */ 483 PROBE_ATTACH_MODE_LINK, 484 }; 485 486 struct bpf_kprobe_opts { 487 /* size of this struct, for forward/backward compatibility */ 488 size_t sz; 489 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 490 __u64 bpf_cookie; 491 /* function's offset to install kprobe to */ 492 size_t offset; 493 /* kprobe is return probe */ 494 bool retprobe; 495 /* kprobe attach mode */ 496 enum probe_attach_mode attach_mode; 497 size_t :0; 498 }; 499 #define bpf_kprobe_opts__last_field attach_mode 500 501 LIBBPF_API struct bpf_link * 502 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, 503 const char *func_name); 504 LIBBPF_API struct bpf_link * 505 bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 506 const char *func_name, 507 const struct bpf_kprobe_opts *opts); 508 509 struct bpf_kprobe_multi_opts { 510 /* size of this struct, for forward/backward compatibility */ 511 size_t sz; 512 /* array of function symbols to attach */ 513 const char **syms; 514 /* array of function addresses to attach */ 515 const unsigned long *addrs; 516 /* array of user-provided values fetchable through bpf_get_attach_cookie */ 517 const __u64 *cookies; 518 /* number of elements in syms/addrs/cookies arrays */ 519 size_t cnt; 520 /* create return kprobes */ 521 bool retprobe; 522 size_t :0; 523 }; 524 525 #define bpf_kprobe_multi_opts__last_field retprobe 526 527 LIBBPF_API struct bpf_link * 528 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 529 const char *pattern, 530 const struct bpf_kprobe_multi_opts *opts); 531 532 struct bpf_ksyscall_opts { 533 /* size of this struct, for forward/backward compatibility */ 534 size_t sz; 535 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 536 __u64 bpf_cookie; 537 /* attach as return probe? */ 538 bool retprobe; 539 size_t :0; 540 }; 541 #define bpf_ksyscall_opts__last_field retprobe 542 543 /** 544 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program 545 * to kernel syscall handler of a specified syscall. Optionally it's possible 546 * to request to install retprobe that will be triggered at syscall exit. It's 547 * also possible to associate BPF cookie (though options). 548 * 549 * Libbpf automatically will determine correct full kernel function name, 550 * which depending on system architecture and kernel version/configuration 551 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will 552 * attach specified program using kprobe/kretprobe mechanism. 553 * 554 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative 555 * **SEC("ksyscall/<syscall>")** annotation of BPF programs. 556 * 557 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do 558 * not handle all the calling convention quirks for mmap(), clone() and compat 559 * syscalls. It also only attaches to "native" syscall interfaces. If host 560 * system supports compat syscalls or defines 32-bit syscalls in 64-bit 561 * kernel, such syscall interfaces won't be attached to by libbpf. 562 * 563 * These limitations may or may not change in the future. Therefore it is 564 * recommended to use SEC("kprobe") for these syscalls or if working with 565 * compat and 32-bit interfaces is required. 566 * 567 * @param prog BPF program to attach 568 * @param syscall_name Symbolic name of the syscall (e.g., "bpf") 569 * @param opts Additional options (see **struct bpf_ksyscall_opts**) 570 * @return Reference to the newly created BPF link; or NULL is returned on 571 * error, error code is stored in errno 572 */ 573 LIBBPF_API struct bpf_link * 574 bpf_program__attach_ksyscall(const struct bpf_program *prog, 575 const char *syscall_name, 576 const struct bpf_ksyscall_opts *opts); 577 578 struct bpf_uprobe_opts { 579 /* size of this struct, for forward/backward compatibility */ 580 size_t sz; 581 /* offset of kernel reference counted USDT semaphore, added in 582 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 583 */ 584 size_t ref_ctr_offset; 585 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 586 __u64 bpf_cookie; 587 /* uprobe is return probe, invoked at function return time */ 588 bool retprobe; 589 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 590 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 591 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 592 * offset within a function, specify func_name and use func_offset argument to specify 593 * offset within the function. Shared library functions must specify the shared library 594 * binary_path. 595 */ 596 const char *func_name; 597 /* uprobe attach mode */ 598 enum probe_attach_mode attach_mode; 599 size_t :0; 600 }; 601 #define bpf_uprobe_opts__last_field attach_mode 602 603 /** 604 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 605 * to the userspace function which is found by binary path and 606 * offset. You can optionally specify a particular proccess to attach 607 * to. You can also optionally attach the program to the function 608 * exit instead of entry. 609 * 610 * @param prog BPF program to attach 611 * @param retprobe Attach to function exit 612 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 613 * -1 for all processes 614 * @param binary_path Path to binary that contains the function symbol 615 * @param func_offset Offset within the binary of the function symbol 616 * @return Reference to the newly created BPF link; or NULL is returned on error, 617 * error code is stored in errno 618 */ 619 LIBBPF_API struct bpf_link * 620 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 621 pid_t pid, const char *binary_path, 622 size_t func_offset); 623 624 /** 625 * @brief **bpf_program__attach_uprobe_opts()** is just like 626 * bpf_program__attach_uprobe() except with a options struct 627 * for various configurations. 628 * 629 * @param prog BPF program to attach 630 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 631 * -1 for all processes 632 * @param binary_path Path to binary that contains the function symbol 633 * @param func_offset Offset within the binary of the function symbol 634 * @param opts Options for altering program attachment 635 * @return Reference to the newly created BPF link; or NULL is returned on error, 636 * error code is stored in errno 637 */ 638 LIBBPF_API struct bpf_link * 639 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 640 const char *binary_path, size_t func_offset, 641 const struct bpf_uprobe_opts *opts); 642 643 struct bpf_usdt_opts { 644 /* size of this struct, for forward/backward compatibility */ 645 size_t sz; 646 /* custom user-provided value accessible through usdt_cookie() */ 647 __u64 usdt_cookie; 648 size_t :0; 649 }; 650 #define bpf_usdt_opts__last_field usdt_cookie 651 652 /** 653 * @brief **bpf_program__attach_usdt()** is just like 654 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 655 * Statically Defined Tracepoint) attachment, instead of attaching to 656 * user-space function entry or exit. 657 * 658 * @param prog BPF program to attach 659 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 660 * -1 for all processes 661 * @param binary_path Path to binary that contains provided USDT probe 662 * @param usdt_provider USDT provider name 663 * @param usdt_name USDT probe name 664 * @param opts Options for altering program attachment 665 * @return Reference to the newly created BPF link; or NULL is returned on error, 666 * error code is stored in errno 667 */ 668 LIBBPF_API struct bpf_link * 669 bpf_program__attach_usdt(const struct bpf_program *prog, 670 pid_t pid, const char *binary_path, 671 const char *usdt_provider, const char *usdt_name, 672 const struct bpf_usdt_opts *opts); 673 674 struct bpf_tracepoint_opts { 675 /* size of this struct, for forward/backward compatibility */ 676 size_t sz; 677 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 678 __u64 bpf_cookie; 679 }; 680 #define bpf_tracepoint_opts__last_field bpf_cookie 681 682 LIBBPF_API struct bpf_link * 683 bpf_program__attach_tracepoint(const struct bpf_program *prog, 684 const char *tp_category, 685 const char *tp_name); 686 LIBBPF_API struct bpf_link * 687 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 688 const char *tp_category, 689 const char *tp_name, 690 const struct bpf_tracepoint_opts *opts); 691 692 LIBBPF_API struct bpf_link * 693 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 694 const char *tp_name); 695 696 struct bpf_trace_opts { 697 /* size of this struct, for forward/backward compatibility */ 698 size_t sz; 699 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 700 __u64 cookie; 701 }; 702 #define bpf_trace_opts__last_field cookie 703 704 LIBBPF_API struct bpf_link * 705 bpf_program__attach_trace(const struct bpf_program *prog); 706 LIBBPF_API struct bpf_link * 707 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 708 709 LIBBPF_API struct bpf_link * 710 bpf_program__attach_lsm(const struct bpf_program *prog); 711 LIBBPF_API struct bpf_link * 712 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 713 LIBBPF_API struct bpf_link * 714 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 715 LIBBPF_API struct bpf_link * 716 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 717 LIBBPF_API struct bpf_link * 718 bpf_program__attach_freplace(const struct bpf_program *prog, 719 int target_fd, const char *attach_func_name); 720 721 struct bpf_map; 722 723 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 724 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); 725 726 struct bpf_iter_attach_opts { 727 size_t sz; /* size of this struct for forward/backward compatibility */ 728 union bpf_iter_link_info *link_info; 729 __u32 link_info_len; 730 }; 731 #define bpf_iter_attach_opts__last_field link_info_len 732 733 LIBBPF_API struct bpf_link * 734 bpf_program__attach_iter(const struct bpf_program *prog, 735 const struct bpf_iter_attach_opts *opts); 736 737 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 738 739 /** 740 * @brief **bpf_program__set_type()** sets the program 741 * type of the passed BPF program. 742 * @param prog BPF program to set the program type for 743 * @param type program type to set the BPF map to have 744 * @return error code; or 0 if no error. An error occurs 745 * if the object is already loaded. 746 * 747 * This must be called before the BPF object is loaded, 748 * otherwise it has no effect and an error is returned. 749 */ 750 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 751 enum bpf_prog_type type); 752 753 LIBBPF_API enum bpf_attach_type 754 bpf_program__expected_attach_type(const struct bpf_program *prog); 755 756 /** 757 * @brief **bpf_program__set_expected_attach_type()** sets the 758 * attach type of the passed BPF program. This is used for 759 * auto-detection of attachment when programs are loaded. 760 * @param prog BPF program to set the attach type for 761 * @param type attach type to set the BPF map to have 762 * @return error code; or 0 if no error. An error occurs 763 * if the object is already loaded. 764 * 765 * This must be called before the BPF object is loaded, 766 * otherwise it has no effect and an error is returned. 767 */ 768 LIBBPF_API int 769 bpf_program__set_expected_attach_type(struct bpf_program *prog, 770 enum bpf_attach_type type); 771 772 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 773 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 774 775 /* Per-program log level and log buffer getters/setters. 776 * See bpf_object_open_opts comments regarding log_level and log_buf 777 * interactions. 778 */ 779 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 780 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 781 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 782 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 783 784 /** 785 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 786 * for supported BPF program types: 787 * - BTF-aware raw tracepoints (tp_btf); 788 * - fentry/fexit/fmod_ret; 789 * - lsm; 790 * - freplace. 791 * @param prog BPF program to set the attach type for 792 * @param type attach type to set the BPF map to have 793 * @return error code; or 0 if no error occurred. 794 */ 795 LIBBPF_API int 796 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 797 const char *attach_func_name); 798 799 /** 800 * @brief **bpf_object__find_map_by_name()** returns BPF map of 801 * the given name, if it exists within the passed BPF object 802 * @param obj BPF object 803 * @param name name of the BPF map 804 * @return BPF map instance, if such map exists within the BPF object; 805 * or NULL otherwise. 806 */ 807 LIBBPF_API struct bpf_map * 808 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 809 810 LIBBPF_API int 811 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 812 813 LIBBPF_API struct bpf_map * 814 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 815 816 #define bpf_object__for_each_map(pos, obj) \ 817 for ((pos) = bpf_object__next_map((obj), NULL); \ 818 (pos) != NULL; \ 819 (pos) = bpf_object__next_map((obj), (pos))) 820 #define bpf_map__for_each bpf_object__for_each_map 821 822 LIBBPF_API struct bpf_map * 823 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 824 825 /** 826 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 827 * BPF map during BPF object load phase. 828 * @param map the BPF map instance 829 * @param autocreate whether to create BPF map during BPF object load 830 * @return 0 on success; -EBUSY if BPF object was already loaded 831 * 832 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 833 * BPF map. By default, libbpf will attempt to create every single BPF map 834 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 835 * and fill in map FD in BPF instructions. 836 * 837 * This API allows to opt-out of this process for specific map instance. This 838 * can be useful if host kernel doesn't support such BPF map type or used 839 * combination of flags and user application wants to avoid creating such 840 * a map in the first place. User is still responsible to make sure that their 841 * BPF-side code that expects to use such missing BPF map is recognized by BPF 842 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 843 */ 844 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 845 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 846 847 /** 848 * @brief **bpf_map__fd()** gets the file descriptor of the passed 849 * BPF map 850 * @param map the BPF map instance 851 * @return the file descriptor; or -EINVAL in case of an error 852 */ 853 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 854 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 855 /* get map name */ 856 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 857 /* get/set map type */ 858 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 859 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 860 /* get/set map size (max_entries) */ 861 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 862 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 863 /* get/set map flags */ 864 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 865 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 866 /* get/set map NUMA node */ 867 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 868 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 869 /* get/set map key size */ 870 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 871 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 872 /* get map value size */ 873 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 874 /** 875 * @brief **bpf_map__set_value_size()** sets map value size. 876 * @param map the BPF map instance 877 * @return 0, on success; negative error, otherwise 878 * 879 * There is a special case for maps with associated memory-mapped regions, like 880 * the global data section maps (bss, data, rodata). When this function is used 881 * on such a map, the mapped region is resized. Afterward, an attempt is made to 882 * adjust the corresponding BTF info. This attempt is best-effort and can only 883 * succeed if the last variable of the data section map is an array. The array 884 * BTF type is replaced by a new BTF array type with a different length. 885 * Any previously existing pointers returned from bpf_map__initial_value() or 886 * corresponding data section skeleton pointer must be reinitialized. 887 */ 888 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 889 /* get map key/value BTF type IDs */ 890 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 891 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 892 /* get/set map if_index */ 893 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 894 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 895 /* get/set map map_extra flags */ 896 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 897 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 898 899 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 900 const void *data, size_t size); 901 LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize); 902 903 /** 904 * @brief **bpf_map__is_internal()** tells the caller whether or not the 905 * passed map is a special map created by libbpf automatically for things like 906 * global variables, __ksym externs, Kconfig values, etc 907 * @param map the bpf_map 908 * @return true, if the map is an internal map; false, otherwise 909 */ 910 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 911 912 /** 913 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the 914 * BPF map should be pinned. This does not actually create the 'pin'. 915 * @param map The bpf_map 916 * @param path The path 917 * @return 0, on success; negative error, otherwise 918 */ 919 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 920 921 /** 922 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the 923 * BPF map should be pinned. 924 * @param map The bpf_map 925 * @return The path string; which can be NULL 926 */ 927 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 928 929 /** 930 * @brief **bpf_map__is_pinned()** tells the caller whether or not the 931 * passed map has been pinned via a 'pin' file. 932 * @param map The bpf_map 933 * @return true, if the map is pinned; false, otherwise 934 */ 935 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 936 937 /** 938 * @brief **bpf_map__pin()** creates a file that serves as a 'pin' 939 * for the BPF map. This increments the reference count on the 940 * BPF map which will keep the BPF map loaded even after the 941 * userspace process which loaded it has exited. 942 * @param map The bpf_map to pin 943 * @param path A file path for the 'pin' 944 * @return 0, on success; negative error, otherwise 945 * 946 * If `path` is NULL the maps `pin_path` attribute will be used. If this is 947 * also NULL, an error will be returned and the map will not be pinned. 948 */ 949 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 950 951 /** 952 * @brief **bpf_map__unpin()** removes the file that serves as a 953 * 'pin' for the BPF map. 954 * @param map The bpf_map to unpin 955 * @param path A file path for the 'pin' 956 * @return 0, on success; negative error, otherwise 957 * 958 * The `path` parameter can be NULL, in which case the `pin_path` 959 * map attribute is unpinned. If both the `path` parameter and 960 * `pin_path` map attribute are set, they must be equal. 961 */ 962 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 963 964 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 965 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 966 967 /** 968 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 969 * corresponding to provided key. 970 * @param map BPF map to lookup element in 971 * @param key pointer to memory containing bytes of the key used for lookup 972 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 973 * @param value pointer to memory in which looked up value will be stored 974 * @param value_sz size in byte of value data memory; it has to match BPF map 975 * definition's **value_size**. For per-CPU BPF maps value size has to be 976 * a product of BPF map value size and number of possible CPUs in the system 977 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 978 * per-CPU values value size has to be aligned up to closest 8 bytes for 979 * alignment reasons, so expected size is: `round_up(value_size, 8) 980 * * libbpf_num_possible_cpus()`. 981 * @flags extra flags passed to kernel for this operation 982 * @return 0, on success; negative error, otherwise 983 * 984 * **bpf_map__lookup_elem()** is high-level equivalent of 985 * **bpf_map_lookup_elem()** API with added check for key and value size. 986 */ 987 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 988 const void *key, size_t key_sz, 989 void *value, size_t value_sz, __u64 flags); 990 991 /** 992 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 993 * map that corresponds to provided key. 994 * @param map BPF map to insert to or update element in 995 * @param key pointer to memory containing bytes of the key 996 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 997 * @param value pointer to memory containing bytes of the value 998 * @param value_sz size in byte of value data memory; it has to match BPF map 999 * definition's **value_size**. For per-CPU BPF maps value size has to be 1000 * a product of BPF map value size and number of possible CPUs in the system 1001 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1002 * per-CPU values value size has to be aligned up to closest 8 bytes for 1003 * alignment reasons, so expected size is: `round_up(value_size, 8) 1004 * * libbpf_num_possible_cpus()`. 1005 * @flags extra flags passed to kernel for this operation 1006 * @return 0, on success; negative error, otherwise 1007 * 1008 * **bpf_map__update_elem()** is high-level equivalent of 1009 * **bpf_map_update_elem()** API with added check for key and value size. 1010 */ 1011 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 1012 const void *key, size_t key_sz, 1013 const void *value, size_t value_sz, __u64 flags); 1014 1015 /** 1016 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 1017 * corresponds to provided key. 1018 * @param map BPF map to delete element from 1019 * @param key pointer to memory containing bytes of the key 1020 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1021 * @flags extra flags passed to kernel for this operation 1022 * @return 0, on success; negative error, otherwise 1023 * 1024 * **bpf_map__delete_elem()** is high-level equivalent of 1025 * **bpf_map_delete_elem()** API with added check for key size. 1026 */ 1027 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 1028 const void *key, size_t key_sz, __u64 flags); 1029 1030 /** 1031 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 1032 * corresponding to provided key and atomically delete it afterwards. 1033 * @param map BPF map to lookup element in 1034 * @param key pointer to memory containing bytes of the key used for lookup 1035 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1036 * @param value pointer to memory in which looked up value will be stored 1037 * @param value_sz size in byte of value data memory; it has to match BPF map 1038 * definition's **value_size**. For per-CPU BPF maps value size has to be 1039 * a product of BPF map value size and number of possible CPUs in the system 1040 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1041 * per-CPU values value size has to be aligned up to closest 8 bytes for 1042 * alignment reasons, so expected size is: `round_up(value_size, 8) 1043 * * libbpf_num_possible_cpus()`. 1044 * @flags extra flags passed to kernel for this operation 1045 * @return 0, on success; negative error, otherwise 1046 * 1047 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 1048 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 1049 */ 1050 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 1051 const void *key, size_t key_sz, 1052 void *value, size_t value_sz, __u64 flags); 1053 1054 /** 1055 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 1056 * fetching next key that follows current key. 1057 * @param map BPF map to fetch next key from 1058 * @param cur_key pointer to memory containing bytes of current key or NULL to 1059 * fetch the first key 1060 * @param next_key pointer to memory to write next key into 1061 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1062 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 1063 * negative error, otherwise 1064 * 1065 * **bpf_map__get_next_key()** is high-level equivalent of 1066 * **bpf_map_get_next_key()** API with added check for key size. 1067 */ 1068 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 1069 const void *cur_key, void *next_key, size_t key_sz); 1070 1071 struct bpf_xdp_set_link_opts { 1072 size_t sz; 1073 int old_fd; 1074 size_t :0; 1075 }; 1076 #define bpf_xdp_set_link_opts__last_field old_fd 1077 1078 struct bpf_xdp_attach_opts { 1079 size_t sz; 1080 int old_prog_fd; 1081 size_t :0; 1082 }; 1083 #define bpf_xdp_attach_opts__last_field old_prog_fd 1084 1085 struct bpf_xdp_query_opts { 1086 size_t sz; 1087 __u32 prog_id; /* output */ 1088 __u32 drv_prog_id; /* output */ 1089 __u32 hw_prog_id; /* output */ 1090 __u32 skb_prog_id; /* output */ 1091 __u8 attach_mode; /* output */ 1092 __u64 feature_flags; /* output */ 1093 size_t :0; 1094 }; 1095 #define bpf_xdp_query_opts__last_field feature_flags 1096 1097 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 1098 const struct bpf_xdp_attach_opts *opts); 1099 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 1100 const struct bpf_xdp_attach_opts *opts); 1101 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 1102 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 1103 1104 /* TC related API */ 1105 enum bpf_tc_attach_point { 1106 BPF_TC_INGRESS = 1 << 0, 1107 BPF_TC_EGRESS = 1 << 1, 1108 BPF_TC_CUSTOM = 1 << 2, 1109 }; 1110 1111 #define BPF_TC_PARENT(a, b) \ 1112 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 1113 1114 enum bpf_tc_flags { 1115 BPF_TC_F_REPLACE = 1 << 0, 1116 }; 1117 1118 struct bpf_tc_hook { 1119 size_t sz; 1120 int ifindex; 1121 enum bpf_tc_attach_point attach_point; 1122 __u32 parent; 1123 size_t :0; 1124 }; 1125 #define bpf_tc_hook__last_field parent 1126 1127 struct bpf_tc_opts { 1128 size_t sz; 1129 int prog_fd; 1130 __u32 flags; 1131 __u32 prog_id; 1132 __u32 handle; 1133 __u32 priority; 1134 size_t :0; 1135 }; 1136 #define bpf_tc_opts__last_field priority 1137 1138 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 1139 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 1140 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 1141 struct bpf_tc_opts *opts); 1142 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 1143 const struct bpf_tc_opts *opts); 1144 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 1145 struct bpf_tc_opts *opts); 1146 1147 /* Ring buffer APIs */ 1148 struct ring_buffer; 1149 struct user_ring_buffer; 1150 1151 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 1152 1153 struct ring_buffer_opts { 1154 size_t sz; /* size of this struct, for forward/backward compatibility */ 1155 }; 1156 1157 #define ring_buffer_opts__last_field sz 1158 1159 LIBBPF_API struct ring_buffer * 1160 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 1161 const struct ring_buffer_opts *opts); 1162 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 1163 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 1164 ring_buffer_sample_fn sample_cb, void *ctx); 1165 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 1166 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 1167 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 1168 1169 struct user_ring_buffer_opts { 1170 size_t sz; /* size of this struct, for forward/backward compatibility */ 1171 }; 1172 1173 #define user_ring_buffer_opts__last_field sz 1174 1175 /** 1176 * @brief **user_ring_buffer__new()** creates a new instance of a user ring 1177 * buffer. 1178 * 1179 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map. 1180 * @param opts Options for how the ring buffer should be created. 1181 * @return A user ring buffer on success; NULL and errno being set on a 1182 * failure. 1183 */ 1184 LIBBPF_API struct user_ring_buffer * 1185 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); 1186 1187 /** 1188 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the 1189 * user ring buffer. 1190 * @param rb A pointer to a user ring buffer. 1191 * @param size The size of the sample, in bytes. 1192 * @return A pointer to an 8-byte aligned reserved region of the user ring 1193 * buffer; NULL, and errno being set if a sample could not be reserved. 1194 * 1195 * This function is *not* thread safe, and callers must synchronize accessing 1196 * this function if there are multiple producers. If a size is requested that 1197 * is larger than the size of the entire ring buffer, errno will be set to 1198 * E2BIG and NULL is returned. If the ring buffer could accommodate the size, 1199 * but currently does not have enough space, errno is set to ENOSPC and NULL is 1200 * returned. 1201 * 1202 * After initializing the sample, callers must invoke 1203 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise, 1204 * the sample must be freed with **user_ring_buffer__discard()**. 1205 */ 1206 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); 1207 1208 /** 1209 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the 1210 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes 1211 * available. 1212 * @param rb The user ring buffer. 1213 * @param size The size of the sample, in bytes. 1214 * @param timeout_ms The amount of time, in milliseconds, for which the caller 1215 * should block when waiting for a sample. -1 causes the caller to block 1216 * indefinitely. 1217 * @return A pointer to an 8-byte aligned reserved region of the user ring 1218 * buffer; NULL, and errno being set if a sample could not be reserved. 1219 * 1220 * This function is *not* thread safe, and callers must synchronize 1221 * accessing this function if there are multiple producers 1222 * 1223 * If **timeout_ms** is -1, the function will block indefinitely until a sample 1224 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno 1225 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking 1226 * will occur and the function will return immediately after attempting to 1227 * reserve a sample. 1228 * 1229 * If **size** is larger than the size of the entire ring buffer, errno is set 1230 * to E2BIG and NULL is returned. If the ring buffer could accommodate 1231 * **size**, but currently does not have enough space, the caller will block 1232 * until at most **timeout_ms** has elapsed. If insufficient space is available 1233 * at that time, errno is set to ENOSPC, and NULL is returned. 1234 * 1235 * The kernel guarantees that it will wake up this thread to check if 1236 * sufficient space is available in the ring buffer at least once per 1237 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at 1238 * least one sample is consumed, and the BPF program did not invoke the 1239 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the 1240 * kernel does not guarantee this. If the helper function is invoked with 1241 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is 1242 * consumed. 1243 * 1244 * When a sample of size **size** is found within **timeout_ms**, a pointer to 1245 * the sample is returned. After initializing the sample, callers must invoke 1246 * **user_ring_buffer__submit()** to post the sample to the ring buffer. 1247 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**. 1248 */ 1249 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, 1250 __u32 size, 1251 int timeout_ms); 1252 1253 /** 1254 * @brief **user_ring_buffer__submit()** submits a previously reserved sample 1255 * into the ring buffer. 1256 * @param rb The user ring buffer. 1257 * @param sample A reserved sample. 1258 * 1259 * It is not necessary to synchronize amongst multiple producers when invoking 1260 * this function. 1261 */ 1262 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); 1263 1264 /** 1265 * @brief **user_ring_buffer__discard()** discards a previously reserved sample. 1266 * @param rb The user ring buffer. 1267 * @param sample A reserved sample. 1268 * 1269 * It is not necessary to synchronize amongst multiple producers when invoking 1270 * this function. 1271 */ 1272 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample); 1273 1274 /** 1275 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously 1276 * created with **user_ring_buffer__new()**. 1277 * @param rb The user ring buffer being freed. 1278 */ 1279 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb); 1280 1281 /* Perf buffer APIs */ 1282 struct perf_buffer; 1283 1284 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 1285 void *data, __u32 size); 1286 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 1287 1288 /* common use perf buffer options */ 1289 struct perf_buffer_opts { 1290 size_t sz; 1291 __u32 sample_period; 1292 size_t :0; 1293 }; 1294 #define perf_buffer_opts__last_field sample_period 1295 1296 /** 1297 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1298 * BPF_PERF_EVENT_ARRAY map 1299 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1300 * code to send data over to user-space 1301 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1302 * @param sample_cb function called on each received data record 1303 * @param lost_cb function called when record loss has occurred 1304 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1305 * @return a new instance of struct perf_buffer on success, NULL on error with 1306 * *errno* containing an error code 1307 */ 1308 LIBBPF_API struct perf_buffer * 1309 perf_buffer__new(int map_fd, size_t page_cnt, 1310 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1311 const struct perf_buffer_opts *opts); 1312 1313 enum bpf_perf_event_ret { 1314 LIBBPF_PERF_EVENT_DONE = 0, 1315 LIBBPF_PERF_EVENT_ERROR = -1, 1316 LIBBPF_PERF_EVENT_CONT = -2, 1317 }; 1318 1319 struct perf_event_header; 1320 1321 typedef enum bpf_perf_event_ret 1322 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1323 1324 /* raw perf buffer options, giving most power and control */ 1325 struct perf_buffer_raw_opts { 1326 size_t sz; 1327 long :0; 1328 long :0; 1329 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1330 * max_entries of given PERF_EVENT_ARRAY map) 1331 */ 1332 int cpu_cnt; 1333 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1334 int *cpus; 1335 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1336 int *map_keys; 1337 }; 1338 #define perf_buffer_raw_opts__last_field map_keys 1339 1340 struct perf_event_attr; 1341 1342 LIBBPF_API struct perf_buffer * 1343 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1344 perf_buffer_event_fn event_cb, void *ctx, 1345 const struct perf_buffer_raw_opts *opts); 1346 1347 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1348 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1349 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1350 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1351 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1352 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1353 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1354 /** 1355 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying 1356 * memory region of the ring buffer. 1357 * This ring buffer can be used to implement a custom events consumer. 1358 * The ring buffer starts with the *struct perf_event_mmap_page*, which 1359 * holds the ring buffer managment fields, when accessing the header 1360 * structure it's important to be SMP aware. 1361 * You can refer to *perf_event_read_simple* for a simple example. 1362 * @param pb the perf buffer structure 1363 * @param buf_idx the buffer index to retreive 1364 * @param buf (out) gets the base pointer of the mmap()'ed memory 1365 * @param buf_size (out) gets the size of the mmap()'ed region 1366 * @return 0 on success, negative error code for failure 1367 */ 1368 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, 1369 size_t *buf_size); 1370 1371 struct bpf_prog_linfo; 1372 struct bpf_prog_info; 1373 1374 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1375 LIBBPF_API struct bpf_prog_linfo * 1376 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1377 LIBBPF_API const struct bpf_line_info * 1378 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1379 __u64 addr, __u32 func_idx, __u32 nr_skip); 1380 LIBBPF_API const struct bpf_line_info * 1381 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1382 __u32 insn_off, __u32 nr_skip); 1383 1384 /* 1385 * Probe for supported system features 1386 * 1387 * Note that running many of these probes in a short amount of time can cause 1388 * the kernel to reach the maximal size of lockable memory allowed for the 1389 * user, causing subsequent probes to fail. In this case, the caller may want 1390 * to adjust that limit with setrlimit(). 1391 */ 1392 1393 /** 1394 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1395 * BPF programs of a given type. 1396 * @param prog_type BPF program type to detect kernel support for 1397 * @param opts reserved for future extensibility, should be NULL 1398 * @return 1, if given program type is supported; 0, if given program type is 1399 * not supported; negative error code if feature detection failed or can't be 1400 * performed 1401 * 1402 * Make sure the process has required set of CAP_* permissions (or runs as 1403 * root) when performing feature checking. 1404 */ 1405 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1406 /** 1407 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1408 * BPF maps of a given type. 1409 * @param map_type BPF map type to detect kernel support for 1410 * @param opts reserved for future extensibility, should be NULL 1411 * @return 1, if given map type is supported; 0, if given map type is 1412 * not supported; negative error code if feature detection failed or can't be 1413 * performed 1414 * 1415 * Make sure the process has required set of CAP_* permissions (or runs as 1416 * root) when performing feature checking. 1417 */ 1418 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1419 /** 1420 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1421 * use of a given BPF helper from specified BPF program type. 1422 * @param prog_type BPF program type used to check the support of BPF helper 1423 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1424 * @param opts reserved for future extensibility, should be NULL 1425 * @return 1, if given combination of program type and helper is supported; 0, 1426 * if the combination is not supported; negative error code if feature 1427 * detection for provided input arguments failed or can't be performed 1428 * 1429 * Make sure the process has required set of CAP_* permissions (or runs as 1430 * root) when performing feature checking. 1431 */ 1432 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1433 enum bpf_func_id helper_id, const void *opts); 1434 1435 /** 1436 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1437 * number of possible CPUs that the host kernel supports and expects. 1438 * @return number of possible CPUs; or error code on failure 1439 * 1440 * Example usage: 1441 * 1442 * int ncpus = libbpf_num_possible_cpus(); 1443 * if (ncpus < 0) { 1444 * // error handling 1445 * } 1446 * long values[ncpus]; 1447 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1448 */ 1449 LIBBPF_API int libbpf_num_possible_cpus(void); 1450 1451 struct bpf_map_skeleton { 1452 const char *name; 1453 struct bpf_map **map; 1454 void **mmaped; 1455 }; 1456 1457 struct bpf_prog_skeleton { 1458 const char *name; 1459 struct bpf_program **prog; 1460 struct bpf_link **link; 1461 }; 1462 1463 struct bpf_object_skeleton { 1464 size_t sz; /* size of this struct, for forward/backward compatibility */ 1465 1466 const char *name; 1467 const void *data; 1468 size_t data_sz; 1469 1470 struct bpf_object **obj; 1471 1472 int map_cnt; 1473 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1474 struct bpf_map_skeleton *maps; 1475 1476 int prog_cnt; 1477 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1478 struct bpf_prog_skeleton *progs; 1479 }; 1480 1481 LIBBPF_API int 1482 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1483 const struct bpf_object_open_opts *opts); 1484 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1485 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1486 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1487 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1488 1489 struct bpf_var_skeleton { 1490 const char *name; 1491 struct bpf_map **map; 1492 void **addr; 1493 }; 1494 1495 struct bpf_object_subskeleton { 1496 size_t sz; /* size of this struct, for forward/backward compatibility */ 1497 1498 const struct bpf_object *obj; 1499 1500 int map_cnt; 1501 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1502 struct bpf_map_skeleton *maps; 1503 1504 int prog_cnt; 1505 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1506 struct bpf_prog_skeleton *progs; 1507 1508 int var_cnt; 1509 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1510 struct bpf_var_skeleton *vars; 1511 }; 1512 1513 LIBBPF_API int 1514 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1515 LIBBPF_API void 1516 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1517 1518 struct gen_loader_opts { 1519 size_t sz; /* size of this struct, for forward/backward compatibility */ 1520 const char *data; 1521 const char *insns; 1522 __u32 data_sz; 1523 __u32 insns_sz; 1524 }; 1525 1526 #define gen_loader_opts__last_field insns_sz 1527 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1528 struct gen_loader_opts *opts); 1529 1530 enum libbpf_tristate { 1531 TRI_NO = 0, 1532 TRI_YES = 1, 1533 TRI_MODULE = 2, 1534 }; 1535 1536 struct bpf_linker_opts { 1537 /* size of this struct, for forward/backward compatibility */ 1538 size_t sz; 1539 }; 1540 #define bpf_linker_opts__last_field sz 1541 1542 struct bpf_linker_file_opts { 1543 /* size of this struct, for forward/backward compatibility */ 1544 size_t sz; 1545 }; 1546 #define bpf_linker_file_opts__last_field sz 1547 1548 struct bpf_linker; 1549 1550 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1551 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1552 const char *filename, 1553 const struct bpf_linker_file_opts *opts); 1554 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1555 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1556 1557 /* 1558 * Custom handling of BPF program's SEC() definitions 1559 */ 1560 1561 struct bpf_prog_load_opts; /* defined in bpf.h */ 1562 1563 /* Called during bpf_object__open() for each recognized BPF program. Callback 1564 * can use various bpf_program__set_*() setters to adjust whatever properties 1565 * are necessary. 1566 */ 1567 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1568 1569 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1570 * into the kernel. Callback can adjust opts as necessary. 1571 */ 1572 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1573 struct bpf_prog_load_opts *opts, long cookie); 1574 1575 /* Called during skeleton attach or through bpf_program__attach(). If 1576 * auto-attach is not supported, callback should return 0 and set link to 1577 * NULL (it's not considered an error during skeleton attach, but it will be 1578 * an error for bpf_program__attach() calls). On error, error should be 1579 * returned directly and link set to NULL. On success, return 0 and set link 1580 * to a valid struct bpf_link. 1581 */ 1582 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1583 struct bpf_link **link); 1584 1585 struct libbpf_prog_handler_opts { 1586 /* size of this struct, for forward/backward compatibility */ 1587 size_t sz; 1588 /* User-provided value that is passed to prog_setup_fn, 1589 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1590 * register one set of callbacks for multiple SEC() definitions and 1591 * still be able to distinguish them, if necessary. For example, 1592 * libbpf itself is using this to pass necessary flags (e.g., 1593 * sleepable flag) to a common internal SEC() handler. 1594 */ 1595 long cookie; 1596 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1597 * Callback is optional, pass NULL if it's not necessary. 1598 */ 1599 libbpf_prog_setup_fn_t prog_setup_fn; 1600 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1601 * Callback is optional, pass NULL if it's not necessary. 1602 */ 1603 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1604 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1605 * Callback is optional, pass NULL if it's not necessary. 1606 */ 1607 libbpf_prog_attach_fn_t prog_attach_fn; 1608 }; 1609 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1610 1611 /** 1612 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1613 * SEC() handler. 1614 * @param sec section prefix for which custom handler is registered 1615 * @param prog_type BPF program type associated with specified section 1616 * @param exp_attach_type Expected BPF attach type associated with specified section 1617 * @param opts optional cookie, callbacks, and other extra options 1618 * @return Non-negative handler ID is returned on success. This handler ID has 1619 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1620 * custom handler. Negative error code is returned on error. 1621 * 1622 * *sec* defines which SEC() definitions are handled by this custom handler 1623 * registration. *sec* can have few different forms: 1624 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1625 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1626 * in an error; 1627 * - if *sec* is of the form "abc/", proper SEC() form is 1628 * SEC("abc/something"), where acceptable "something" should be checked by 1629 * *prog_init_fn* callback, if there are additional restrictions; 1630 * - if *sec* is of the form "abc+", it will successfully match both 1631 * SEC("abc") and SEC("abc/whatever") forms; 1632 * - if *sec* is NULL, custom handler is registered for any BPF program that 1633 * doesn't match any of the registered (custom or libbpf's own) SEC() 1634 * handlers. There could be only one such generic custom handler registered 1635 * at any given time. 1636 * 1637 * All custom handlers (except the one with *sec* == NULL) are processed 1638 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1639 * SEC() handlers by registering custom ones for the same section prefix 1640 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1641 * handler). 1642 * 1643 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1644 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1645 * to ensure synchronization if there is a risk of running this API from 1646 * multiple threads simultaneously. 1647 */ 1648 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 1649 enum bpf_prog_type prog_type, 1650 enum bpf_attach_type exp_attach_type, 1651 const struct libbpf_prog_handler_opts *opts); 1652 /** 1653 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 1654 * custom BPF program SEC() handler. 1655 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 1656 * after successful registration 1657 * @return 0 on success, negative error code if handler isn't found 1658 * 1659 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1660 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1661 * to ensure synchronization if there is a risk of running this API from 1662 * multiple threads simultaneously. 1663 */ 1664 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 1665 1666 #ifdef __cplusplus 1667 } /* extern "C" */ 1668 #endif 1669 1670 #endif /* __LIBBPF_LIBBPF_H */ 1671