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 /** 28 * @brief **libbpf_major_version()** provides the major version of libbpf. 29 * @return An integer, the major version number 30 */ 31 LIBBPF_API __u32 libbpf_major_version(void); 32 33 /** 34 * @brief **libbpf_minor_version()** provides the minor version of libbpf. 35 * @return An integer, the minor version number 36 */ 37 LIBBPF_API __u32 libbpf_minor_version(void); 38 39 /** 40 * @brief **libbpf_version_string()** provides the version of libbpf in a 41 * human-readable form, e.g., "v1.7". 42 * @return Pointer to a static string containing the version 43 * 44 * The format is *not* a part of a stable API and may change in the future. 45 */ 46 LIBBPF_API const char *libbpf_version_string(void); 47 48 enum libbpf_errno { 49 __LIBBPF_ERRNO__START = 4000, 50 51 /* Something wrong in libelf */ 52 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 53 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 54 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 55 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 56 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 57 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 58 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 59 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 60 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 61 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 62 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 63 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 64 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 65 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 66 __LIBBPF_ERRNO__END, 67 }; 68 69 /** 70 * @brief **libbpf_strerror()** converts the provided error code into a 71 * human-readable string. 72 * @param err The error code to convert 73 * @param buf Pointer to a buffer where the error message will be stored 74 * @param size The number of bytes in the buffer 75 * @return 0, on success; negative error code, otherwise 76 */ 77 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 78 79 /** 80 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type 81 * value into a textual representation. 82 * @param t The attach type. 83 * @return Pointer to a static string identifying the attach type. NULL is 84 * returned for unknown **bpf_attach_type** values. 85 */ 86 LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t); 87 88 /** 89 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value 90 * into a textual representation. 91 * @param t The link type. 92 * @return Pointer to a static string identifying the link type. NULL is 93 * returned for unknown **bpf_link_type** values. 94 */ 95 LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t); 96 97 /** 98 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value 99 * into a textual representation. 100 * @param t The map type. 101 * @return Pointer to a static string identifying the map type. NULL is 102 * returned for unknown **bpf_map_type** values. 103 */ 104 LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t); 105 106 /** 107 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type 108 * value into a textual representation. 109 * @param t The program type. 110 * @return Pointer to a static string identifying the program type. NULL is 111 * returned for unknown **bpf_prog_type** values. 112 */ 113 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t); 114 115 enum libbpf_print_level { 116 LIBBPF_WARN, 117 LIBBPF_INFO, 118 LIBBPF_DEBUG, 119 }; 120 121 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, 122 const char *, va_list ap); 123 124 /** 125 * @brief **libbpf_set_print()** sets user-provided log callback function to 126 * be used for libbpf warnings and informational messages. If the user callback 127 * is not set, messages are logged to stderr by default. The verbosity of these 128 * messages can be controlled by setting the environment variable 129 * LIBBPF_LOG_LEVEL to either warn, info, or debug. 130 * @param fn The log print function. If NULL, libbpf won't print anything. 131 * @return Pointer to old print function. 132 * 133 * This function is thread-safe. 134 */ 135 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); 136 137 /* Hide internal to user */ 138 struct bpf_object; 139 140 struct bpf_object_open_opts { 141 /* size of this struct, for forward/backward compatibility */ 142 size_t sz; 143 /* object name override, if provided: 144 * - for object open from file, this will override setting object 145 * name from file path's base name; 146 * - for object open from memory buffer, this will specify an object 147 * name and will override default "<addr>-<buf-size>" name; 148 */ 149 const char *object_name; 150 /* parse map definitions non-strictly, allowing extra attributes/data */ 151 bool relaxed_maps; 152 /* maps that set the 'pinning' attribute in their definition will have 153 * their pin_path attribute set to a file in this directory, and be 154 * auto-pinned to that path on load; defaults to "/sys/fs/bpf". 155 */ 156 const char *pin_root_path; 157 158 __u32 :32; /* stub out now removed attach_prog_fd */ 159 160 /* Additional kernel config content that augments and overrides 161 * system Kconfig for CONFIG_xxx externs. 162 */ 163 const char *kconfig; 164 /* Path to the custom BTF to be used for BPF CO-RE relocations. 165 * This custom BTF completely replaces the use of vmlinux BTF 166 * for the purpose of CO-RE relocations. 167 * NOTE: any other BPF feature (e.g., fentry/fexit programs, 168 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. 169 */ 170 const char *btf_custom_path; 171 /* Pointer to a buffer for storing kernel logs for applicable BPF 172 * commands. Valid kernel_log_size has to be specified as well and are 173 * passed-through to bpf() syscall. Keep in mind that kernel might 174 * fail operation with -ENOSPC error if provided buffer is too small 175 * to contain entire log output. 176 * See the comment below for kernel_log_level for interaction between 177 * log_buf and log_level settings. 178 * 179 * If specified, this log buffer will be passed for: 180 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overridden 181 * with bpf_program__set_log() on per-program level, to get 182 * BPF verifier log output. 183 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get 184 * BTF sanity checking log. 185 * 186 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite 187 * previous contents, so if you need more fine-grained control, set 188 * per-program buffer with bpf_program__set_log_buf() to preserve each 189 * individual program's verification log. Keep using kernel_log_buf 190 * for BTF verification log, if necessary. 191 */ 192 char *kernel_log_buf; 193 size_t kernel_log_size; 194 /* 195 * Log level can be set independently from log buffer. Log_level=0 196 * means that libbpf will attempt loading BTF or program without any 197 * logging requested, but will retry with either its own or custom log 198 * buffer, if provided, and log_level=1 on any error. 199 * And vice versa, setting log_level>0 will request BTF or prog 200 * loading with verbose log from the first attempt (and as such also 201 * for successfully loaded BTF or program), and the actual log buffer 202 * could be either libbpf's own auto-allocated log buffer, if 203 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. 204 * If user didn't provide custom log buffer, libbpf will emit captured 205 * logs through its print callback. 206 */ 207 __u32 kernel_log_level; 208 /* Path to BPF FS mount point to derive BPF token from. 209 * 210 * Created BPF token will be used for all bpf() syscall operations 211 * that accept BPF token (e.g., map creation, BTF and program loads, 212 * etc) automatically within instantiated BPF object. 213 * 214 * If bpf_token_path is not specified, libbpf will consult 215 * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be 216 * taken as a value of bpf_token_path option and will force libbpf to 217 * either create BPF token from provided custom BPF FS path, or will 218 * disable implicit BPF token creation, if envvar value is an empty 219 * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are 220 * set at the same time. 221 * 222 * Setting bpf_token_path option to empty string disables libbpf's 223 * automatic attempt to create BPF token from default BPF FS mount 224 * point (/sys/fs/bpf), in case this default behavior is undesirable. 225 */ 226 const char *bpf_token_path; 227 228 size_t :0; 229 }; 230 #define bpf_object_open_opts__last_field bpf_token_path 231 232 /** 233 * @brief **bpf_object__open()** creates a bpf_object by opening 234 * the BPF ELF object file pointed to by the passed path and loading it 235 * into memory. 236 * @param path BPF object file path. 237 * @return pointer to the new bpf_object; or NULL is returned on error, 238 * error code is stored in errno 239 */ 240 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 241 242 /** 243 * @brief **bpf_object__open_file()** creates a bpf_object by opening 244 * the BPF ELF object file pointed to by the passed path and loading it 245 * into memory. 246 * @param path BPF object file path 247 * @param opts options for how to load the bpf object, this parameter is 248 * optional and can be set to NULL 249 * @return pointer to the new bpf_object; or NULL is returned on error, 250 * error code is stored in errno 251 */ 252 LIBBPF_API struct bpf_object * 253 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); 254 255 /** 256 * @brief **bpf_object__open_mem()** creates a bpf_object by reading 257 * the BPF objects raw bytes from a memory buffer containing a valid 258 * BPF ELF object file. 259 * @param obj_buf pointer to the buffer containing ELF file bytes 260 * @param obj_buf_sz number of bytes in the buffer 261 * @param opts options for how to load the bpf object 262 * @return pointer to the new bpf_object; or NULL is returned on error, 263 * error code is stored in errno 264 */ 265 LIBBPF_API struct bpf_object * 266 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, 267 const struct bpf_object_open_opts *opts); 268 269 /** 270 * @brief **bpf_object__prepare()** prepares BPF object for loading: 271 * performs ELF processing, relocations, prepares final state of BPF program 272 * instructions (accessible with bpf_program__insns()), creates and 273 * (potentially) pins maps. Leaves BPF object in the state ready for program 274 * loading. 275 * @param obj Pointer to a valid BPF object instance returned by 276 * **bpf_object__open*()** API 277 * @return 0, on success; negative error code, otherwise, error code is 278 * stored in errno 279 */ 280 LIBBPF_API int bpf_object__prepare(struct bpf_object *obj); 281 282 /** 283 * @brief **bpf_object__load()** loads BPF object into kernel. 284 * @param obj Pointer to a valid BPF object instance returned by 285 * **bpf_object__open*()** APIs 286 * @return 0, on success; negative error code, otherwise, error code is 287 * stored in errno 288 */ 289 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 290 291 /** 292 * @brief **bpf_object__close()** closes a BPF object and releases all 293 * resources. 294 * @param obj Pointer to a valid BPF object 295 */ 296 LIBBPF_API void bpf_object__close(struct bpf_object *obj); 297 298 /** 299 * @brief **bpf_object__pin_maps()** pins each map contained within 300 * the BPF object at the passed directory. 301 * @param obj Pointer to a valid BPF object 302 * @param path A directory where maps should be pinned. 303 * @return 0, on success; negative error code, otherwise 304 * 305 * If `path` is NULL `bpf_map__pin` (which is being used on each map) 306 * will use the pin_path attribute of each map. In this case, maps that 307 * don't have a pin_path set will be ignored. 308 */ 309 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 310 311 /** 312 * @brief **bpf_object__unpin_maps()** unpins each map contained within 313 * the BPF object found in the passed directory. 314 * @param obj Pointer to a valid BPF object 315 * @param path A directory where pinned maps should be searched for. 316 * @return 0, on success; negative error code, otherwise 317 * 318 * If `path` is NULL `bpf_map__unpin` (which is being used on each map) 319 * will use the pin_path attribute of each map. In this case, maps that 320 * don't have a pin_path set will be ignored. 321 */ 322 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 323 const char *path); 324 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 325 const char *path); 326 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 327 const char *path); 328 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 329 LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path); 330 331 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); 332 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); 333 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); 334 335 /** 336 * @brief **bpf_object__token_fd** is an accessor for BPF token FD associated 337 * with BPF object. 338 * @param obj Pointer to a valid BPF object 339 * @return BPF token FD or -1, if it wasn't set 340 */ 341 LIBBPF_API int bpf_object__token_fd(const struct bpf_object *obj); 342 343 struct btf; 344 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); 345 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 346 347 LIBBPF_API struct bpf_program * 348 bpf_object__find_program_by_name(const struct bpf_object *obj, 349 const char *name); 350 351 LIBBPF_API int 352 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 353 enum bpf_attach_type *expected_attach_type); 354 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 355 enum bpf_attach_type *attach_type); 356 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, 357 enum bpf_attach_type attach_type); 358 359 /* Accessors of bpf_program */ 360 struct bpf_program; 361 362 LIBBPF_API struct bpf_program * 363 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); 364 365 #define bpf_object__for_each_program(pos, obj) \ 366 for ((pos) = bpf_object__next_program((obj), NULL); \ 367 (pos) != NULL; \ 368 (pos) = bpf_object__next_program((obj), (pos))) 369 370 LIBBPF_API struct bpf_program * 371 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); 372 373 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 374 __u32 ifindex); 375 376 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); 377 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); 378 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); 379 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); 380 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog); 381 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach); 382 383 struct bpf_insn; 384 385 /** 386 * @brief **bpf_program__insns()** gives read-only access to BPF program's 387 * underlying BPF instructions. 388 * @param prog BPF program for which to return instructions 389 * @return a pointer to an array of BPF instructions that belong to the 390 * specified BPF program 391 * 392 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` 393 * pointed to can be fetched using **bpf_program__insn_cnt()** API. 394 * 395 * Keep in mind, libbpf can modify and append/delete BPF program's 396 * instructions as it processes BPF object file and prepares everything for 397 * uploading into the kernel. So depending on the point in BPF object 398 * lifetime, **bpf_program__insns()** can return different sets of 399 * instructions. As an example, during BPF object load phase BPF program 400 * instructions will be CO-RE-relocated, BPF subprograms instructions will be 401 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions 402 * returned before **bpf_object__load()** and after it might be quite 403 * different. 404 */ 405 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); 406 407 /** 408 * @brief **bpf_program__set_insns()** can set BPF program's underlying 409 * BPF instructions. 410 * 411 * WARNING: This is a very advanced libbpf API and users need to know 412 * what they are doing. This should be used from prog_prepare_load_fn 413 * callback only. 414 * 415 * @param prog BPF program for which to return instructions 416 * @param new_insns a pointer to an array of BPF instructions 417 * @param new_insn_cnt number of `struct bpf_insn`'s that form 418 * specified BPF program 419 * @return 0, on success; negative error code, otherwise 420 */ 421 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, 422 struct bpf_insn *new_insns, size_t new_insn_cnt); 423 424 /** 425 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s 426 * that form specified BPF program. 427 * @param prog BPF program for which to return number of BPF instructions 428 * 429 * See **bpf_program__insns()** documentation for notes on how libbpf can 430 * change instructions and their count during different phases of 431 * **bpf_object** lifetime. 432 */ 433 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); 434 435 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); 436 437 /** 438 * @brief **bpf_program__pin()** pins the BPF program to a file 439 * in the BPF FS specified by a path. This increments the programs 440 * reference count, allowing it to stay loaded after the process 441 * which loaded it has exited. 442 * 443 * @param prog BPF program to pin, must already be loaded 444 * @param path file path in a BPF file system 445 * @return 0, on success; negative error code, otherwise 446 */ 447 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 448 449 /** 450 * @brief **bpf_program__unpin()** unpins the BPF program from a file 451 * in the BPFFS specified by a path. This decrements program's in-kernel 452 * reference count. 453 * 454 * The file pinning the BPF program can also be unlinked by a different 455 * process in which case this function will return an error. 456 * 457 * @param prog BPF program to unpin 458 * @param path file path to the pin in a BPF file system 459 * @return 0, on success; negative error code, otherwise 460 */ 461 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 462 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 463 464 struct bpf_link; 465 466 LIBBPF_API struct bpf_link *bpf_link__open(const char *path); 467 LIBBPF_API int bpf_link__fd(const struct bpf_link *link); 468 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); 469 /** 470 * @brief **bpf_link__pin()** pins the BPF link to a file 471 * in the BPF FS specified by a path. This increments the links 472 * reference count, allowing it to stay loaded after the process 473 * which loaded it has exited. 474 * 475 * @param link BPF link to pin, must already be loaded 476 * @param path file path in a BPF file system 477 * @return 0, on success; negative error code, otherwise 478 */ 479 480 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); 481 482 /** 483 * @brief **bpf_link__unpin()** unpins the BPF link from a file 484 * in the BPFFS. This decrements link's in-kernel reference count. 485 * 486 * The file pinning the BPF link can also be unlinked by a different 487 * process in which case this function will return an error. 488 * 489 * @param link BPF link to unpin 490 * @return 0, on success; negative error code, otherwise 491 */ 492 LIBBPF_API int bpf_link__unpin(struct bpf_link *link); 493 LIBBPF_API int bpf_link__update_program(struct bpf_link *link, 494 struct bpf_program *prog); 495 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); 496 LIBBPF_API int bpf_link__detach(struct bpf_link *link); 497 LIBBPF_API int bpf_link__destroy(struct bpf_link *link); 498 499 /** 500 * @brief **bpf_program__attach()** is a generic function for attaching 501 * a BPF program based on auto-detection of program type, attach type, 502 * and extra parameters, where applicable. 503 * 504 * @param prog BPF program to attach 505 * @return Reference to the newly created BPF link; or NULL is returned on error, 506 * error code is stored in errno 507 * 508 * This is supported for: 509 * - kprobe/kretprobe (depends on SEC() definition) 510 * - uprobe/uretprobe (depends on SEC() definition) 511 * - tracepoint 512 * - raw tracepoint 513 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) 514 */ 515 LIBBPF_API struct bpf_link * 516 bpf_program__attach(const struct bpf_program *prog); 517 518 struct bpf_perf_event_opts { 519 /* size of this struct, for forward/backward compatibility */ 520 size_t sz; 521 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 522 __u64 bpf_cookie; 523 /* don't use BPF link when attach BPF program */ 524 bool force_ioctl_attach; 525 /* don't automatically enable the event */ 526 bool dont_enable; 527 size_t :0; 528 }; 529 #define bpf_perf_event_opts__last_field dont_enable 530 531 LIBBPF_API struct bpf_link * 532 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); 533 534 LIBBPF_API struct bpf_link * 535 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, 536 const struct bpf_perf_event_opts *opts); 537 538 /** 539 * enum probe_attach_mode - the mode to attach kprobe/uprobe 540 * 541 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will 542 * be returned if it is not supported by the kernel. 543 */ 544 enum probe_attach_mode { 545 /* attach probe in latest supported mode by kernel */ 546 PROBE_ATTACH_MODE_DEFAULT = 0, 547 /* attach probe in legacy mode, using debugfs/tracefs */ 548 PROBE_ATTACH_MODE_LEGACY, 549 /* create perf event with perf_event_open() syscall */ 550 PROBE_ATTACH_MODE_PERF, 551 /* attach probe with BPF link */ 552 PROBE_ATTACH_MODE_LINK, 553 }; 554 555 struct bpf_kprobe_opts { 556 /* size of this struct, for forward/backward compatibility */ 557 size_t sz; 558 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 559 __u64 bpf_cookie; 560 /* function's offset to install kprobe to */ 561 size_t offset; 562 /* kprobe is return probe */ 563 bool retprobe; 564 /* kprobe attach mode */ 565 enum probe_attach_mode attach_mode; 566 size_t :0; 567 }; 568 #define bpf_kprobe_opts__last_field attach_mode 569 570 LIBBPF_API struct bpf_link * 571 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, 572 const char *func_name); 573 LIBBPF_API struct bpf_link * 574 bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 575 const char *func_name, 576 const struct bpf_kprobe_opts *opts); 577 578 struct bpf_kprobe_multi_opts { 579 /* size of this struct, for forward/backward compatibility */ 580 size_t sz; 581 /* array of function symbols to attach */ 582 const char **syms; 583 /* array of function addresses to attach */ 584 const unsigned long *addrs; 585 /* array of user-provided values fetchable through bpf_get_attach_cookie */ 586 const __u64 *cookies; 587 /* number of elements in syms/addrs/cookies arrays */ 588 size_t cnt; 589 /* create return kprobes */ 590 bool retprobe; 591 /* create session kprobes */ 592 bool session; 593 /* enforce unique match */ 594 bool unique_match; 595 size_t :0; 596 }; 597 598 #define bpf_kprobe_multi_opts__last_field unique_match 599 600 LIBBPF_API struct bpf_link * 601 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 602 const char *pattern, 603 const struct bpf_kprobe_multi_opts *opts); 604 605 struct bpf_uprobe_multi_opts { 606 /* size of this struct, for forward/backward compatibility */ 607 size_t sz; 608 /* array of function symbols to attach to */ 609 const char **syms; 610 /* array of function addresses to attach to */ 611 const unsigned long *offsets; 612 /* optional, array of associated ref counter offsets */ 613 const unsigned long *ref_ctr_offsets; 614 /* optional, array of associated BPF cookies */ 615 const __u64 *cookies; 616 /* number of elements in syms/addrs/cookies arrays */ 617 size_t cnt; 618 /* create return uprobes */ 619 bool retprobe; 620 /* create session kprobes */ 621 bool session; 622 size_t :0; 623 }; 624 625 #define bpf_uprobe_multi_opts__last_field session 626 627 /** 628 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program 629 * to multiple uprobes with uprobe_multi link. 630 * 631 * User can specify 2 mutually exclusive set of inputs: 632 * 633 * 1) use only path/func_pattern/pid arguments 634 * 635 * 2) use path/pid with allowed combinations of 636 * syms/offsets/ref_ctr_offsets/cookies/cnt 637 * 638 * - syms and offsets are mutually exclusive 639 * - ref_ctr_offsets and cookies are optional 640 * 641 * 642 * @param prog BPF program to attach 643 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 644 * -1 for all processes 645 * @param binary_path Path to binary 646 * @param func_pattern Regular expression to specify functions to attach 647 * BPF program to 648 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**) 649 * @return 0, on success; negative error code, otherwise 650 */ 651 LIBBPF_API struct bpf_link * 652 bpf_program__attach_uprobe_multi(const struct bpf_program *prog, 653 pid_t pid, 654 const char *binary_path, 655 const char *func_pattern, 656 const struct bpf_uprobe_multi_opts *opts); 657 658 struct bpf_ksyscall_opts { 659 /* size of this struct, for forward/backward compatibility */ 660 size_t sz; 661 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 662 __u64 bpf_cookie; 663 /* attach as return probe? */ 664 bool retprobe; 665 size_t :0; 666 }; 667 #define bpf_ksyscall_opts__last_field retprobe 668 669 /** 670 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program 671 * to kernel syscall handler of a specified syscall. Optionally it's possible 672 * to request to install retprobe that will be triggered at syscall exit. It's 673 * also possible to associate BPF cookie (though options). 674 * 675 * Libbpf automatically will determine correct full kernel function name, 676 * which depending on system architecture and kernel version/configuration 677 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will 678 * attach specified program using kprobe/kretprobe mechanism. 679 * 680 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative 681 * **SEC("ksyscall/<syscall>")** annotation of BPF programs. 682 * 683 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do 684 * not handle all the calling convention quirks for mmap(), clone() and compat 685 * syscalls. It also only attaches to "native" syscall interfaces. If host 686 * system supports compat syscalls or defines 32-bit syscalls in 64-bit 687 * kernel, such syscall interfaces won't be attached to by libbpf. 688 * 689 * These limitations may or may not change in the future. Therefore it is 690 * recommended to use SEC("kprobe") for these syscalls or if working with 691 * compat and 32-bit interfaces is required. 692 * 693 * @param prog BPF program to attach 694 * @param syscall_name Symbolic name of the syscall (e.g., "bpf") 695 * @param opts Additional options (see **struct bpf_ksyscall_opts**) 696 * @return Reference to the newly created BPF link; or NULL is returned on 697 * error, error code is stored in errno 698 */ 699 LIBBPF_API struct bpf_link * 700 bpf_program__attach_ksyscall(const struct bpf_program *prog, 701 const char *syscall_name, 702 const struct bpf_ksyscall_opts *opts); 703 704 struct bpf_uprobe_opts { 705 /* size of this struct, for forward/backward compatibility */ 706 size_t sz; 707 /* offset of kernel reference counted USDT semaphore, added in 708 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 709 */ 710 size_t ref_ctr_offset; 711 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 712 __u64 bpf_cookie; 713 /* uprobe is return probe, invoked at function return time */ 714 bool retprobe; 715 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 716 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 717 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 718 * offset within a function, specify func_name and use func_offset argument to specify 719 * offset within the function. Shared library functions must specify the shared library 720 * binary_path. 721 */ 722 const char *func_name; 723 /* uprobe attach mode */ 724 enum probe_attach_mode attach_mode; 725 size_t :0; 726 }; 727 #define bpf_uprobe_opts__last_field attach_mode 728 729 /** 730 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 731 * to the userspace function which is found by binary path and 732 * offset. You can optionally specify a particular process to attach 733 * to. You can also optionally attach the program to the function 734 * exit instead of entry. 735 * 736 * @param prog BPF program to attach 737 * @param retprobe Attach to function exit 738 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 739 * -1 for all processes 740 * @param binary_path Path to binary that contains the function symbol 741 * @param func_offset Offset within the binary of the function symbol 742 * @return Reference to the newly created BPF link; or NULL is returned on error, 743 * error code is stored in errno 744 */ 745 LIBBPF_API struct bpf_link * 746 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 747 pid_t pid, const char *binary_path, 748 size_t func_offset); 749 750 /** 751 * @brief **bpf_program__attach_uprobe_opts()** is just like 752 * bpf_program__attach_uprobe() except with a options struct 753 * for various configurations. 754 * 755 * @param prog BPF program to attach 756 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 757 * -1 for all processes 758 * @param binary_path Path to binary that contains the function symbol 759 * @param func_offset Offset within the binary of the function symbol 760 * @param opts Options for altering program attachment 761 * @return Reference to the newly created BPF link; or NULL is returned on error, 762 * error code is stored in errno 763 */ 764 LIBBPF_API struct bpf_link * 765 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 766 const char *binary_path, size_t func_offset, 767 const struct bpf_uprobe_opts *opts); 768 769 struct bpf_usdt_opts { 770 /* size of this struct, for forward/backward compatibility */ 771 size_t sz; 772 /* custom user-provided value accessible through usdt_cookie() */ 773 __u64 usdt_cookie; 774 size_t :0; 775 }; 776 #define bpf_usdt_opts__last_field usdt_cookie 777 778 /** 779 * @brief **bpf_program__attach_usdt()** is just like 780 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 781 * Statically Defined Tracepoint) attachment, instead of attaching to 782 * user-space function entry or exit. 783 * 784 * @param prog BPF program to attach 785 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 786 * -1 for all processes 787 * @param binary_path Path to binary that contains provided USDT probe 788 * @param usdt_provider USDT provider name 789 * @param usdt_name USDT probe name 790 * @param opts Options for altering program attachment 791 * @return Reference to the newly created BPF link; or NULL is returned on error, 792 * error code is stored in errno 793 */ 794 LIBBPF_API struct bpf_link * 795 bpf_program__attach_usdt(const struct bpf_program *prog, 796 pid_t pid, const char *binary_path, 797 const char *usdt_provider, const char *usdt_name, 798 const struct bpf_usdt_opts *opts); 799 800 struct bpf_tracepoint_opts { 801 /* size of this struct, for forward/backward compatibility */ 802 size_t sz; 803 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 804 __u64 bpf_cookie; 805 }; 806 #define bpf_tracepoint_opts__last_field bpf_cookie 807 808 LIBBPF_API struct bpf_link * 809 bpf_program__attach_tracepoint(const struct bpf_program *prog, 810 const char *tp_category, 811 const char *tp_name); 812 LIBBPF_API struct bpf_link * 813 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 814 const char *tp_category, 815 const char *tp_name, 816 const struct bpf_tracepoint_opts *opts); 817 818 struct bpf_raw_tracepoint_opts { 819 size_t sz; /* size of this struct for forward/backward compatibility */ 820 __u64 cookie; 821 size_t :0; 822 }; 823 #define bpf_raw_tracepoint_opts__last_field cookie 824 825 LIBBPF_API struct bpf_link * 826 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 827 const char *tp_name); 828 LIBBPF_API struct bpf_link * 829 bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog, 830 const char *tp_name, 831 struct bpf_raw_tracepoint_opts *opts); 832 833 struct bpf_trace_opts { 834 /* size of this struct, for forward/backward compatibility */ 835 size_t sz; 836 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 837 __u64 cookie; 838 }; 839 #define bpf_trace_opts__last_field cookie 840 841 LIBBPF_API struct bpf_link * 842 bpf_program__attach_trace(const struct bpf_program *prog); 843 LIBBPF_API struct bpf_link * 844 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 845 846 LIBBPF_API struct bpf_link * 847 bpf_program__attach_lsm(const struct bpf_program *prog); 848 LIBBPF_API struct bpf_link * 849 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 850 LIBBPF_API struct bpf_link * 851 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 852 LIBBPF_API struct bpf_link * 853 bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd); 854 LIBBPF_API struct bpf_link * 855 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 856 LIBBPF_API struct bpf_link * 857 bpf_program__attach_freplace(const struct bpf_program *prog, 858 int target_fd, const char *attach_func_name); 859 860 struct bpf_netfilter_opts { 861 /* size of this struct, for forward/backward compatibility */ 862 size_t sz; 863 864 __u32 pf; 865 __u32 hooknum; 866 __s32 priority; 867 __u32 flags; 868 }; 869 #define bpf_netfilter_opts__last_field flags 870 871 LIBBPF_API struct bpf_link * 872 bpf_program__attach_netfilter(const struct bpf_program *prog, 873 const struct bpf_netfilter_opts *opts); 874 875 struct bpf_tcx_opts { 876 /* size of this struct, for forward/backward compatibility */ 877 size_t sz; 878 __u32 flags; 879 __u32 relative_fd; 880 __u32 relative_id; 881 __u64 expected_revision; 882 size_t :0; 883 }; 884 #define bpf_tcx_opts__last_field expected_revision 885 886 LIBBPF_API struct bpf_link * 887 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, 888 const struct bpf_tcx_opts *opts); 889 890 struct bpf_netkit_opts { 891 /* size of this struct, for forward/backward compatibility */ 892 size_t sz; 893 __u32 flags; 894 __u32 relative_fd; 895 __u32 relative_id; 896 __u64 expected_revision; 897 size_t :0; 898 }; 899 #define bpf_netkit_opts__last_field expected_revision 900 901 LIBBPF_API struct bpf_link * 902 bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex, 903 const struct bpf_netkit_opts *opts); 904 905 struct bpf_cgroup_opts { 906 /* size of this struct, for forward/backward compatibility */ 907 size_t sz; 908 __u32 flags; 909 __u32 relative_fd; 910 __u32 relative_id; 911 __u64 expected_revision; 912 size_t :0; 913 }; 914 #define bpf_cgroup_opts__last_field expected_revision 915 916 LIBBPF_API struct bpf_link * 917 bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, 918 const struct bpf_cgroup_opts *opts); 919 920 struct bpf_map; 921 922 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 923 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); 924 925 struct bpf_iter_attach_opts { 926 size_t sz; /* size of this struct for forward/backward compatibility */ 927 union bpf_iter_link_info *link_info; 928 __u32 link_info_len; 929 }; 930 #define bpf_iter_attach_opts__last_field link_info_len 931 932 LIBBPF_API struct bpf_link * 933 bpf_program__attach_iter(const struct bpf_program *prog, 934 const struct bpf_iter_attach_opts *opts); 935 936 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 937 938 /** 939 * @brief **bpf_program__set_type()** sets the program 940 * type of the passed BPF program. 941 * @param prog BPF program to set the program type for 942 * @param type program type to set the BPF map to have 943 * @return error code; or 0 if no error. An error occurs 944 * if the object is already loaded. 945 * 946 * This must be called before the BPF object is loaded, 947 * otherwise it has no effect and an error is returned. 948 */ 949 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 950 enum bpf_prog_type type); 951 952 LIBBPF_API enum bpf_attach_type 953 bpf_program__expected_attach_type(const struct bpf_program *prog); 954 955 /** 956 * @brief **bpf_program__set_expected_attach_type()** sets the 957 * attach type of the passed BPF program. This is used for 958 * auto-detection of attachment when programs are loaded. 959 * @param prog BPF program to set the attach type for 960 * @param type attach type to set the BPF map to have 961 * @return error code; or 0 if no error. An error occurs 962 * if the object is already loaded. 963 * 964 * This must be called before the BPF object is loaded, 965 * otherwise it has no effect and an error is returned. 966 */ 967 LIBBPF_API int 968 bpf_program__set_expected_attach_type(struct bpf_program *prog, 969 enum bpf_attach_type type); 970 971 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 972 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 973 974 /* Per-program log level and log buffer getters/setters. 975 * See bpf_object_open_opts comments regarding log_level and log_buf 976 * interactions. 977 */ 978 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 979 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 980 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 981 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 982 983 LIBBPF_API struct bpf_func_info *bpf_program__func_info(const struct bpf_program *prog); 984 LIBBPF_API __u32 bpf_program__func_info_cnt(const struct bpf_program *prog); 985 986 LIBBPF_API struct bpf_line_info *bpf_program__line_info(const struct bpf_program *prog); 987 LIBBPF_API __u32 bpf_program__line_info_cnt(const struct bpf_program *prog); 988 989 /** 990 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 991 * for supported BPF program types: 992 * - BTF-aware raw tracepoints (tp_btf); 993 * - fentry/fexit/fmod_ret; 994 * - lsm; 995 * - freplace. 996 * @param prog BPF program to configure; must be not yet loaded. 997 * @param attach_prog_fd FD of target BPF program (for freplace/extension). 998 * If >0 and func name omitted, defers BTF ID resolution. 999 * @param attach_func_name Target function name. Used either with 1000 * attach_prog_fd to find destination BTF type ID in that BPF program, or 1001 * alone (no attach_prog_fd) to resolve kernel (vmlinux/module) BTF ID. 1002 * Must be provided if attach_prog_fd is 0. 1003 * @return error code; or 0 if no error occurred. 1004 */ 1005 LIBBPF_API int 1006 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 1007 const char *attach_func_name); 1008 1009 struct bpf_prog_assoc_struct_ops_opts; /* defined in bpf.h */ 1010 1011 /** 1012 * @brief **bpf_program__assoc_struct_ops()** associates a BPF program with a 1013 * struct_ops map. 1014 * 1015 * @param prog BPF program 1016 * @param map struct_ops map to be associated with the BPF program 1017 * @param opts optional options, can be NULL 1018 * 1019 * @return 0, on success; negative error code, otherwise 1020 */ 1021 LIBBPF_API int 1022 bpf_program__assoc_struct_ops(struct bpf_program *prog, struct bpf_map *map, 1023 struct bpf_prog_assoc_struct_ops_opts *opts); 1024 1025 /** 1026 * @brief **bpf_object__find_map_by_name()** returns BPF map of 1027 * the given name, if it exists within the passed BPF object 1028 * @param obj BPF object 1029 * @param name name of the BPF map 1030 * @return BPF map instance, if such map exists within the BPF object; 1031 * or NULL otherwise. 1032 */ 1033 LIBBPF_API struct bpf_map * 1034 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 1035 1036 LIBBPF_API int 1037 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 1038 1039 LIBBPF_API struct bpf_map * 1040 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 1041 1042 #define bpf_object__for_each_map(pos, obj) \ 1043 for ((pos) = bpf_object__next_map((obj), NULL); \ 1044 (pos) != NULL; \ 1045 (pos) = bpf_object__next_map((obj), (pos))) 1046 #define bpf_map__for_each bpf_object__for_each_map 1047 1048 LIBBPF_API struct bpf_map * 1049 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 1050 1051 /** 1052 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 1053 * BPF map during BPF object load phase. 1054 * @param map the BPF map instance 1055 * @param autocreate whether to create BPF map during BPF object load 1056 * @return 0 on success; -EBUSY if BPF object was already loaded 1057 * 1058 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 1059 * BPF map. By default, libbpf will attempt to create every single BPF map 1060 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 1061 * and fill in map FD in BPF instructions. 1062 * 1063 * This API allows to opt-out of this process for specific map instance. This 1064 * can be useful if host kernel doesn't support such BPF map type or used 1065 * combination of flags and user application wants to avoid creating such 1066 * a map in the first place. User is still responsible to make sure that their 1067 * BPF-side code that expects to use such missing BPF map is recognized by BPF 1068 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 1069 */ 1070 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 1071 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 1072 1073 /** 1074 * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach 1075 * map during BPF skeleton attach phase. 1076 * @param map the BPF map instance 1077 * @param autoattach whether to attach map during BPF skeleton attach phase 1078 * @return 0 on success; negative error code, otherwise 1079 */ 1080 LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach); 1081 1082 /** 1083 * @brief **bpf_map__autoattach()** returns whether BPF map is configured to 1084 * auto-attach during BPF skeleton attach phase. 1085 * @param map the BPF map instance 1086 * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise 1087 */ 1088 LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map); 1089 1090 /** 1091 * @brief **bpf_map__fd()** gets the file descriptor of the passed 1092 * BPF map 1093 * @param map the BPF map instance 1094 * @return the file descriptor; or -EINVAL in case of an error 1095 */ 1096 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 1097 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 1098 /* get map name */ 1099 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 1100 /* get/set map type */ 1101 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 1102 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 1103 /* get/set map size (max_entries) */ 1104 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 1105 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 1106 /* get/set map flags */ 1107 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 1108 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 1109 /* get/set map NUMA node */ 1110 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 1111 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 1112 /* get/set map key size */ 1113 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 1114 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 1115 /* get map value size */ 1116 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 1117 /** 1118 * @brief **bpf_map__set_value_size()** sets map value size. 1119 * @param map the BPF map instance 1120 * @param size the new value size 1121 * @return 0, on success; negative error, otherwise 1122 * 1123 * There is a special case for maps with associated memory-mapped regions, like 1124 * the global data section maps (bss, data, rodata). When this function is used 1125 * on such a map, the mapped region is resized. Afterward, an attempt is made to 1126 * adjust the corresponding BTF info. This attempt is best-effort and can only 1127 * succeed if the last variable of the data section map is an array. The array 1128 * BTF type is replaced by a new BTF array type with a different length. 1129 * Any previously existing pointers returned from bpf_map__initial_value() or 1130 * corresponding data section skeleton pointer must be reinitialized. 1131 */ 1132 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 1133 /* get map key/value BTF type IDs */ 1134 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 1135 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 1136 /* get/set map if_index */ 1137 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 1138 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 1139 /* get/set map map_extra flags */ 1140 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 1141 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 1142 1143 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 1144 const void *data, size_t size); 1145 LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize); 1146 1147 /** 1148 * @brief **bpf_map__is_internal()** tells the caller whether or not the 1149 * passed map is a special map created by libbpf automatically for things like 1150 * global variables, __ksym externs, Kconfig values, etc 1151 * @param map the bpf_map 1152 * @return true, if the map is an internal map; false, otherwise 1153 */ 1154 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 1155 1156 /** 1157 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the 1158 * BPF map should be pinned. This does not actually create the 'pin'. 1159 * @param map The bpf_map 1160 * @param path The path 1161 * @return 0, on success; negative error, otherwise 1162 */ 1163 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 1164 1165 /** 1166 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the 1167 * BPF map should be pinned. 1168 * @param map The bpf_map 1169 * @return The path string; which can be NULL 1170 */ 1171 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 1172 1173 /** 1174 * @brief **bpf_map__is_pinned()** tells the caller whether or not the 1175 * passed map has been pinned via a 'pin' file. 1176 * @param map The bpf_map 1177 * @return true, if the map is pinned; false, otherwise 1178 */ 1179 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 1180 1181 /** 1182 * @brief **bpf_map__pin()** creates a file that serves as a 'pin' 1183 * for the BPF map. This increments the reference count on the 1184 * BPF map which will keep the BPF map loaded even after the 1185 * userspace process which loaded it has exited. 1186 * @param map The bpf_map to pin 1187 * @param path A file path for the 'pin' 1188 * @return 0, on success; negative error, otherwise 1189 * 1190 * If `path` is NULL the maps `pin_path` attribute will be used. If this is 1191 * also NULL, an error will be returned and the map will not be pinned. 1192 */ 1193 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 1194 1195 /** 1196 * @brief **bpf_map__unpin()** removes the file that serves as a 1197 * 'pin' for the BPF map. 1198 * @param map The bpf_map to unpin 1199 * @param path A file path for the 'pin' 1200 * @return 0, on success; negative error, otherwise 1201 * 1202 * The `path` parameter can be NULL, in which case the `pin_path` 1203 * map attribute is unpinned. If both the `path` parameter and 1204 * `pin_path` map attribute are set, they must be equal. 1205 */ 1206 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 1207 1208 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 1209 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 1210 1211 /** 1212 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 1213 * corresponding to provided key. 1214 * @param map BPF map to lookup element in 1215 * @param key pointer to memory containing bytes of the key used for lookup 1216 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1217 * @param value pointer to memory in which looked up value will be stored 1218 * @param value_sz size in byte of value data memory; it has to match BPF map 1219 * definition's **value_size**. For per-CPU BPF maps, value size can be 1220 * `value_size` if either **BPF_F_CPU** or **BPF_F_ALL_CPUS** is specified 1221 * in **flags**, otherwise a product of BPF map value size and number of 1222 * possible CPUs in the system (could be fetched with 1223 * **libbpf_num_possible_cpus()**). Note also that for per-CPU values value 1224 * size has to be aligned up to closest 8 bytes, so expected size is: 1225 * `round_up(value_size, 8) * libbpf_num_possible_cpus()`. 1226 * @param flags extra flags passed to kernel for this operation 1227 * @return 0, on success; negative error, otherwise 1228 * 1229 * **bpf_map__lookup_elem()** is high-level equivalent of 1230 * **bpf_map_lookup_elem()** API with added check for key and value size. 1231 */ 1232 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 1233 const void *key, size_t key_sz, 1234 void *value, size_t value_sz, __u64 flags); 1235 1236 /** 1237 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 1238 * map that corresponds to provided key. 1239 * @param map BPF map to insert to or update element in 1240 * @param key pointer to memory containing bytes of the key 1241 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1242 * @param value pointer to memory containing bytes of the value 1243 * @param value_sz refer to **bpf_map__lookup_elem**'s description.' 1244 * @param flags extra flags passed to kernel for this operation 1245 * @return 0, on success; negative error, otherwise 1246 * 1247 * **bpf_map__update_elem()** is high-level equivalent of 1248 * **bpf_map_update_elem()** API with added check for key and value size. 1249 */ 1250 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 1251 const void *key, size_t key_sz, 1252 const void *value, size_t value_sz, __u64 flags); 1253 1254 /** 1255 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 1256 * corresponds to provided key. 1257 * @param map BPF map to delete element from 1258 * @param key pointer to memory containing bytes of the key 1259 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1260 * @param flags extra flags passed to kernel for this operation 1261 * @return 0, on success; negative error, otherwise 1262 * 1263 * **bpf_map__delete_elem()** is high-level equivalent of 1264 * **bpf_map_delete_elem()** API with added check for key size. 1265 */ 1266 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 1267 const void *key, size_t key_sz, __u64 flags); 1268 1269 /** 1270 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 1271 * corresponding to provided key and atomically delete it afterwards. 1272 * @param map BPF map to lookup element in 1273 * @param key pointer to memory containing bytes of the key used for lookup 1274 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1275 * @param value pointer to memory in which looked up value will be stored 1276 * @param value_sz size in byte of value data memory; it has to match BPF map 1277 * definition's **value_size**. For per-CPU BPF maps value size has to be 1278 * a product of BPF map value size and number of possible CPUs in the system 1279 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1280 * per-CPU values value size has to be aligned up to closest 8 bytes for 1281 * alignment reasons, so expected size is: `round_up(value_size, 8) 1282 * * libbpf_num_possible_cpus()`. 1283 * @param flags extra flags passed to kernel for this operation 1284 * @return 0, on success; negative error, otherwise 1285 * 1286 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 1287 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 1288 */ 1289 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 1290 const void *key, size_t key_sz, 1291 void *value, size_t value_sz, __u64 flags); 1292 1293 /** 1294 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 1295 * fetching next key that follows current key. 1296 * @param map BPF map to fetch next key from 1297 * @param cur_key pointer to memory containing bytes of current key or NULL to 1298 * fetch the first key 1299 * @param next_key pointer to memory to write next key into 1300 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1301 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 1302 * negative error, otherwise 1303 * 1304 * **bpf_map__get_next_key()** is high-level equivalent of 1305 * **bpf_map_get_next_key()** API with added check for key size. 1306 */ 1307 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 1308 const void *cur_key, void *next_key, size_t key_sz); 1309 /** 1310 * @brief **bpf_map__set_exclusive_program()** sets a map to be exclusive to the 1311 * specified program. This must be called *before* the map is created. 1312 * 1313 * @param map BPF map to make exclusive. 1314 * @param prog BPF program to be the exclusive user of the map. Must belong 1315 * to the same bpf_object as the map. 1316 * @return 0 on success; a negative error code otherwise. 1317 * 1318 * This function must be called after the BPF object is opened but before 1319 * it is loaded. Once the object is loaded, only the specified program 1320 * will be able to access the map's contents. 1321 */ 1322 LIBBPF_API int bpf_map__set_exclusive_program(struct bpf_map *map, struct bpf_program *prog); 1323 1324 /** 1325 * @brief **bpf_map__exclusive_program()** returns the exclusive program 1326 * that is registered with the map (if any). 1327 * @param map BPF map to which the exclusive program is registered. 1328 * @return the registered exclusive program. 1329 */ 1330 LIBBPF_API struct bpf_program *bpf_map__exclusive_program(struct bpf_map *map); 1331 1332 struct bpf_xdp_set_link_opts { 1333 size_t sz; 1334 int old_fd; 1335 size_t :0; 1336 }; 1337 #define bpf_xdp_set_link_opts__last_field old_fd 1338 1339 struct bpf_xdp_attach_opts { 1340 size_t sz; 1341 int old_prog_fd; 1342 size_t :0; 1343 }; 1344 #define bpf_xdp_attach_opts__last_field old_prog_fd 1345 1346 struct bpf_xdp_query_opts { 1347 size_t sz; 1348 __u32 prog_id; /* output */ 1349 __u32 drv_prog_id; /* output */ 1350 __u32 hw_prog_id; /* output */ 1351 __u32 skb_prog_id; /* output */ 1352 __u8 attach_mode; /* output */ 1353 __u64 feature_flags; /* output */ 1354 __u32 xdp_zc_max_segs; /* output */ 1355 size_t :0; 1356 }; 1357 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs 1358 1359 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 1360 const struct bpf_xdp_attach_opts *opts); 1361 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 1362 const struct bpf_xdp_attach_opts *opts); 1363 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 1364 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 1365 1366 /* TC related API */ 1367 enum bpf_tc_attach_point { 1368 BPF_TC_INGRESS = 1 << 0, 1369 BPF_TC_EGRESS = 1 << 1, 1370 BPF_TC_CUSTOM = 1 << 2, 1371 BPF_TC_QDISC = 1 << 3, 1372 }; 1373 1374 #define BPF_TC_PARENT(a, b) \ 1375 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 1376 1377 enum bpf_tc_flags { 1378 BPF_TC_F_REPLACE = 1 << 0, 1379 }; 1380 1381 struct bpf_tc_hook { 1382 size_t sz; 1383 int ifindex; 1384 enum bpf_tc_attach_point attach_point; 1385 __u32 parent; 1386 __u32 handle; 1387 const char *qdisc; 1388 size_t :0; 1389 }; 1390 #define bpf_tc_hook__last_field qdisc 1391 1392 struct bpf_tc_opts { 1393 size_t sz; 1394 int prog_fd; 1395 __u32 flags; 1396 __u32 prog_id; 1397 __u32 handle; 1398 __u32 priority; 1399 size_t :0; 1400 }; 1401 #define bpf_tc_opts__last_field priority 1402 1403 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 1404 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 1405 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 1406 struct bpf_tc_opts *opts); 1407 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 1408 const struct bpf_tc_opts *opts); 1409 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 1410 struct bpf_tc_opts *opts); 1411 1412 /* Ring buffer APIs */ 1413 struct ring_buffer; 1414 struct ring; 1415 struct user_ring_buffer; 1416 1417 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 1418 1419 struct ring_buffer_opts { 1420 size_t sz; /* size of this struct, for forward/backward compatibility */ 1421 }; 1422 1423 #define ring_buffer_opts__last_field sz 1424 1425 LIBBPF_API struct ring_buffer * 1426 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 1427 const struct ring_buffer_opts *opts); 1428 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 1429 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 1430 ring_buffer_sample_fn sample_cb, void *ctx); 1431 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 1432 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 1433 LIBBPF_API int ring_buffer__consume_n(struct ring_buffer *rb, size_t n); 1434 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 1435 1436 /** 1437 * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given 1438 * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance. 1439 * 1440 * @param rb A ringbuffer manager object. 1441 * @param idx An index into the ringbuffers contained within the ringbuffer 1442 * manager object. The index is 0-based and corresponds to the order in which 1443 * ring_buffer__add was called. 1444 * @return A ringbuffer object on success; NULL and errno set if the index is 1445 * invalid. 1446 */ 1447 LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb, 1448 unsigned int idx); 1449 1450 /** 1451 * @brief **ring__consumer_pos()** returns the current consumer position in the 1452 * given ringbuffer. 1453 * 1454 * @param r A ringbuffer object. 1455 * @return The current consumer position. 1456 */ 1457 LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r); 1458 1459 /** 1460 * @brief **ring__producer_pos()** returns the current producer position in the 1461 * given ringbuffer. 1462 * 1463 * @param r A ringbuffer object. 1464 * @return The current producer position. 1465 */ 1466 LIBBPF_API unsigned long ring__producer_pos(const struct ring *r); 1467 1468 /** 1469 * @brief **ring__avail_data_size()** returns the number of bytes in the 1470 * ringbuffer not yet consumed. This has no locking associated with it, so it 1471 * can be inaccurate if operations are ongoing while this is called. However, it 1472 * should still show the correct trend over the long-term. 1473 * 1474 * @param r A ringbuffer object. 1475 * @return The number of bytes not yet consumed. 1476 */ 1477 LIBBPF_API size_t ring__avail_data_size(const struct ring *r); 1478 1479 /** 1480 * @brief **ring__size()** returns the total size of the ringbuffer's map data 1481 * area (excluding special producer/consumer pages). Effectively this gives the 1482 * amount of usable bytes of data inside the ringbuffer. 1483 * 1484 * @param r A ringbuffer object. 1485 * @return The total size of the ringbuffer map data area. 1486 */ 1487 LIBBPF_API size_t ring__size(const struct ring *r); 1488 1489 /** 1490 * @brief **ring__map_fd()** returns the file descriptor underlying the given 1491 * ringbuffer. 1492 * 1493 * @param r A ringbuffer object. 1494 * @return The underlying ringbuffer file descriptor 1495 */ 1496 LIBBPF_API int ring__map_fd(const struct ring *r); 1497 1498 /** 1499 * @brief **ring__consume()** consumes available ringbuffer data without event 1500 * polling. 1501 * 1502 * @param r A ringbuffer object. 1503 * @return The number of records consumed (or INT_MAX, whichever is less), or 1504 * a negative number if any of the callbacks return an error. 1505 */ 1506 LIBBPF_API int ring__consume(struct ring *r); 1507 1508 /** 1509 * @brief **ring__consume_n()** consumes up to a requested amount of items from 1510 * a ringbuffer without event polling. 1511 * 1512 * @param r A ringbuffer object. 1513 * @param n Maximum amount of items to consume. 1514 * @return The number of items consumed, or a negative number if any of the 1515 * callbacks return an error. 1516 */ 1517 LIBBPF_API int ring__consume_n(struct ring *r, size_t n); 1518 1519 struct user_ring_buffer_opts { 1520 size_t sz; /* size of this struct, for forward/backward compatibility */ 1521 }; 1522 1523 #define user_ring_buffer_opts__last_field sz 1524 1525 /** 1526 * @brief **user_ring_buffer__new()** creates a new instance of a user ring 1527 * buffer. 1528 * 1529 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map. 1530 * @param opts Options for how the ring buffer should be created. 1531 * @return A user ring buffer on success; NULL and errno being set on a 1532 * failure. 1533 */ 1534 LIBBPF_API struct user_ring_buffer * 1535 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); 1536 1537 /** 1538 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the 1539 * user ring buffer. 1540 * @param rb A pointer to a user ring buffer. 1541 * @param size The size of the sample, in bytes. 1542 * @return A pointer to an 8-byte aligned reserved region of the user ring 1543 * buffer; NULL, and errno being set if a sample could not be reserved. 1544 * 1545 * This function is *not* thread safe, and callers must synchronize accessing 1546 * this function if there are multiple producers. If a size is requested that 1547 * is larger than the size of the entire ring buffer, errno will be set to 1548 * E2BIG and NULL is returned. If the ring buffer could accommodate the size, 1549 * but currently does not have enough space, errno is set to ENOSPC and NULL is 1550 * returned. 1551 * 1552 * After initializing the sample, callers must invoke 1553 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise, 1554 * the sample must be freed with **user_ring_buffer__discard()**. 1555 */ 1556 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); 1557 1558 /** 1559 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the 1560 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes 1561 * available. 1562 * @param rb The user ring buffer. 1563 * @param size The size of the sample, in bytes. 1564 * @param timeout_ms The amount of time, in milliseconds, for which the caller 1565 * should block when waiting for a sample. -1 causes the caller to block 1566 * indefinitely. 1567 * @return A pointer to an 8-byte aligned reserved region of the user ring 1568 * buffer; NULL, and errno being set if a sample could not be reserved. 1569 * 1570 * This function is *not* thread safe, and callers must synchronize 1571 * accessing this function if there are multiple producers 1572 * 1573 * If **timeout_ms** is -1, the function will block indefinitely until a sample 1574 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno 1575 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking 1576 * will occur and the function will return immediately after attempting to 1577 * reserve a sample. 1578 * 1579 * If **size** is larger than the size of the entire ring buffer, errno is set 1580 * to E2BIG and NULL is returned. If the ring buffer could accommodate 1581 * **size**, but currently does not have enough space, the caller will block 1582 * until at most **timeout_ms** has elapsed. If insufficient space is available 1583 * at that time, errno is set to ENOSPC, and NULL is returned. 1584 * 1585 * The kernel guarantees that it will wake up this thread to check if 1586 * sufficient space is available in the ring buffer at least once per 1587 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at 1588 * least one sample is consumed, and the BPF program did not invoke the 1589 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the 1590 * kernel does not guarantee this. If the helper function is invoked with 1591 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is 1592 * consumed. 1593 * 1594 * When a sample of size **size** is found within **timeout_ms**, a pointer to 1595 * the sample is returned. After initializing the sample, callers must invoke 1596 * **user_ring_buffer__submit()** to post the sample to the ring buffer. 1597 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**. 1598 */ 1599 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, 1600 __u32 size, 1601 int timeout_ms); 1602 1603 /** 1604 * @brief **user_ring_buffer__submit()** submits a previously reserved sample 1605 * into the ring buffer. 1606 * @param rb The user ring buffer. 1607 * @param sample A reserved sample. 1608 * 1609 * It is not necessary to synchronize amongst multiple producers when invoking 1610 * this function. 1611 */ 1612 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); 1613 1614 /** 1615 * @brief **user_ring_buffer__discard()** discards a previously reserved sample. 1616 * @param rb The user ring buffer. 1617 * @param sample A reserved sample. 1618 * 1619 * It is not necessary to synchronize amongst multiple producers when invoking 1620 * this function. 1621 */ 1622 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample); 1623 1624 /** 1625 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously 1626 * created with **user_ring_buffer__new()**. 1627 * @param rb The user ring buffer being freed. 1628 */ 1629 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb); 1630 1631 /* Perf buffer APIs */ 1632 struct perf_buffer; 1633 1634 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 1635 void *data, __u32 size); 1636 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 1637 1638 /* common use perf buffer options */ 1639 struct perf_buffer_opts { 1640 size_t sz; 1641 __u32 sample_period; 1642 size_t :0; 1643 }; 1644 #define perf_buffer_opts__last_field sample_period 1645 1646 /** 1647 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1648 * BPF_PERF_EVENT_ARRAY map 1649 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1650 * code to send data over to user-space 1651 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1652 * @param sample_cb function called on each received data record 1653 * @param lost_cb function called when record loss has occurred 1654 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1655 * @param opts optional parameters for the perf buffer, can be null 1656 * @return a new instance of struct perf_buffer on success, NULL on error with 1657 * *errno* containing an error code 1658 */ 1659 LIBBPF_API struct perf_buffer * 1660 perf_buffer__new(int map_fd, size_t page_cnt, 1661 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1662 const struct perf_buffer_opts *opts); 1663 1664 enum bpf_perf_event_ret { 1665 LIBBPF_PERF_EVENT_DONE = 0, 1666 LIBBPF_PERF_EVENT_ERROR = -1, 1667 LIBBPF_PERF_EVENT_CONT = -2, 1668 }; 1669 1670 struct perf_event_header; 1671 1672 typedef enum bpf_perf_event_ret 1673 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1674 1675 /* raw perf buffer options, giving most power and control */ 1676 struct perf_buffer_raw_opts { 1677 size_t sz; 1678 long :0; 1679 long :0; 1680 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1681 * max_entries of given PERF_EVENT_ARRAY map) 1682 */ 1683 int cpu_cnt; 1684 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1685 int *cpus; 1686 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1687 int *map_keys; 1688 }; 1689 #define perf_buffer_raw_opts__last_field map_keys 1690 1691 struct perf_event_attr; 1692 1693 LIBBPF_API struct perf_buffer * 1694 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1695 perf_buffer_event_fn event_cb, void *ctx, 1696 const struct perf_buffer_raw_opts *opts); 1697 1698 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1699 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1700 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1701 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1702 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1703 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1704 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1705 /** 1706 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying 1707 * memory region of the ring buffer. 1708 * This ring buffer can be used to implement a custom events consumer. 1709 * The ring buffer starts with the *struct perf_event_mmap_page*, which 1710 * holds the ring buffer management fields, when accessing the header 1711 * structure it's important to be SMP aware. 1712 * You can refer to *perf_event_read_simple* for a simple example. 1713 * @param pb the perf buffer structure 1714 * @param buf_idx the buffer index to retrieve 1715 * @param buf (out) gets the base pointer of the mmap()'ed memory 1716 * @param buf_size (out) gets the size of the mmap()'ed region 1717 * @return 0 on success, negative error code for failure 1718 */ 1719 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, 1720 size_t *buf_size); 1721 1722 struct bpf_prog_linfo; 1723 struct bpf_prog_info; 1724 1725 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1726 LIBBPF_API struct bpf_prog_linfo * 1727 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1728 LIBBPF_API const struct bpf_line_info * 1729 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1730 __u64 addr, __u32 func_idx, __u32 nr_skip); 1731 LIBBPF_API const struct bpf_line_info * 1732 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1733 __u32 insn_off, __u32 nr_skip); 1734 1735 /* 1736 * Probe for supported system features 1737 * 1738 * Note that running many of these probes in a short amount of time can cause 1739 * the kernel to reach the maximal size of lockable memory allowed for the 1740 * user, causing subsequent probes to fail. In this case, the caller may want 1741 * to adjust that limit with setrlimit(). 1742 */ 1743 1744 /** 1745 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1746 * BPF programs of a given type. 1747 * @param prog_type BPF program type to detect kernel support for 1748 * @param opts reserved for future extensibility, should be NULL 1749 * @return 1, if given program type is supported; 0, if given program type is 1750 * not supported; negative error code if feature detection failed or can't be 1751 * performed 1752 * 1753 * Make sure the process has required set of CAP_* permissions (or runs as 1754 * root) when performing feature checking. 1755 */ 1756 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1757 /** 1758 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1759 * BPF maps of a given type. 1760 * @param map_type BPF map type to detect kernel support for 1761 * @param opts reserved for future extensibility, should be NULL 1762 * @return 1, if given map type is supported; 0, if given map type is 1763 * not supported; negative error code if feature detection failed or can't be 1764 * performed 1765 * 1766 * Make sure the process has required set of CAP_* permissions (or runs as 1767 * root) when performing feature checking. 1768 */ 1769 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1770 /** 1771 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1772 * use of a given BPF helper from specified BPF program type. 1773 * @param prog_type BPF program type used to check the support of BPF helper 1774 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1775 * @param opts reserved for future extensibility, should be NULL 1776 * @return 1, if given combination of program type and helper is supported; 0, 1777 * if the combination is not supported; negative error code if feature 1778 * detection for provided input arguments failed or can't be performed 1779 * 1780 * Make sure the process has required set of CAP_* permissions (or runs as 1781 * root) when performing feature checking. 1782 */ 1783 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1784 enum bpf_func_id helper_id, const void *opts); 1785 1786 /** 1787 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1788 * number of possible CPUs that the host kernel supports and expects. 1789 * @return number of possible CPUs; or error code on failure 1790 * 1791 * Example usage: 1792 * 1793 * int ncpus = libbpf_num_possible_cpus(); 1794 * if (ncpus < 0) { 1795 * // error handling 1796 * } 1797 * long values[ncpus]; 1798 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1799 */ 1800 LIBBPF_API int libbpf_num_possible_cpus(void); 1801 1802 struct bpf_map_skeleton { 1803 const char *name; 1804 struct bpf_map **map; 1805 void **mmaped; 1806 struct bpf_link **link; 1807 }; 1808 1809 struct bpf_prog_skeleton { 1810 const char *name; 1811 struct bpf_program **prog; 1812 struct bpf_link **link; 1813 }; 1814 1815 struct bpf_object_skeleton { 1816 size_t sz; /* size of this struct, for forward/backward compatibility */ 1817 1818 const char *name; 1819 const void *data; 1820 size_t data_sz; 1821 1822 struct bpf_object **obj; 1823 1824 int map_cnt; 1825 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1826 struct bpf_map_skeleton *maps; 1827 1828 int prog_cnt; 1829 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1830 struct bpf_prog_skeleton *progs; 1831 }; 1832 1833 LIBBPF_API int 1834 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1835 const struct bpf_object_open_opts *opts); 1836 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1837 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1838 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1839 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1840 1841 struct bpf_var_skeleton { 1842 const char *name; 1843 struct bpf_map **map; 1844 void **addr; 1845 }; 1846 1847 struct bpf_object_subskeleton { 1848 size_t sz; /* size of this struct, for forward/backward compatibility */ 1849 1850 const struct bpf_object *obj; 1851 1852 int map_cnt; 1853 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1854 struct bpf_map_skeleton *maps; 1855 1856 int prog_cnt; 1857 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1858 struct bpf_prog_skeleton *progs; 1859 1860 int var_cnt; 1861 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1862 struct bpf_var_skeleton *vars; 1863 }; 1864 1865 LIBBPF_API int 1866 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1867 LIBBPF_API void 1868 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1869 1870 struct gen_loader_opts { 1871 size_t sz; /* size of this struct, for forward/backward compatibility */ 1872 const char *data; 1873 const char *insns; 1874 __u32 data_sz; 1875 __u32 insns_sz; 1876 bool gen_hash; 1877 }; 1878 1879 #define gen_loader_opts__last_field gen_hash 1880 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1881 struct gen_loader_opts *opts); 1882 1883 enum libbpf_tristate { 1884 TRI_NO = 0, 1885 TRI_YES = 1, 1886 TRI_MODULE = 2, 1887 }; 1888 1889 struct bpf_linker_opts { 1890 /* size of this struct, for forward/backward compatibility */ 1891 size_t sz; 1892 }; 1893 #define bpf_linker_opts__last_field sz 1894 1895 struct bpf_linker_file_opts { 1896 /* size of this struct, for forward/backward compatibility */ 1897 size_t sz; 1898 }; 1899 #define bpf_linker_file_opts__last_field sz 1900 1901 struct bpf_linker; 1902 1903 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1904 LIBBPF_API struct bpf_linker *bpf_linker__new_fd(int fd, struct bpf_linker_opts *opts); 1905 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1906 const char *filename, 1907 const struct bpf_linker_file_opts *opts); 1908 LIBBPF_API int bpf_linker__add_fd(struct bpf_linker *linker, int fd, 1909 const struct bpf_linker_file_opts *opts); 1910 LIBBPF_API int bpf_linker__add_buf(struct bpf_linker *linker, void *buf, size_t buf_sz, 1911 const struct bpf_linker_file_opts *opts); 1912 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1913 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1914 1915 /* 1916 * Custom handling of BPF program's SEC() definitions 1917 */ 1918 1919 struct bpf_prog_load_opts; /* defined in bpf.h */ 1920 1921 /* Called during bpf_object__open() for each recognized BPF program. Callback 1922 * can use various bpf_program__set_*() setters to adjust whatever properties 1923 * are necessary. 1924 */ 1925 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1926 1927 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1928 * into the kernel. Callback can adjust opts as necessary. 1929 */ 1930 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1931 struct bpf_prog_load_opts *opts, long cookie); 1932 1933 /* Called during skeleton attach or through bpf_program__attach(). If 1934 * auto-attach is not supported, callback should return 0 and set link to 1935 * NULL (it's not considered an error during skeleton attach, but it will be 1936 * an error for bpf_program__attach() calls). On error, error should be 1937 * returned directly and link set to NULL. On success, return 0 and set link 1938 * to a valid struct bpf_link. 1939 */ 1940 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1941 struct bpf_link **link); 1942 1943 struct libbpf_prog_handler_opts { 1944 /* size of this struct, for forward/backward compatibility */ 1945 size_t sz; 1946 /* User-provided value that is passed to prog_setup_fn, 1947 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1948 * register one set of callbacks for multiple SEC() definitions and 1949 * still be able to distinguish them, if necessary. For example, 1950 * libbpf itself is using this to pass necessary flags (e.g., 1951 * sleepable flag) to a common internal SEC() handler. 1952 */ 1953 long cookie; 1954 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1955 * Callback is optional, pass NULL if it's not necessary. 1956 */ 1957 libbpf_prog_setup_fn_t prog_setup_fn; 1958 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1959 * Callback is optional, pass NULL if it's not necessary. 1960 */ 1961 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1962 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1963 * Callback is optional, pass NULL if it's not necessary. 1964 */ 1965 libbpf_prog_attach_fn_t prog_attach_fn; 1966 }; 1967 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1968 1969 /** 1970 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1971 * SEC() handler. 1972 * @param sec section prefix for which custom handler is registered 1973 * @param prog_type BPF program type associated with specified section 1974 * @param exp_attach_type Expected BPF attach type associated with specified section 1975 * @param opts optional cookie, callbacks, and other extra options 1976 * @return Non-negative handler ID is returned on success. This handler ID has 1977 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1978 * custom handler. Negative error code is returned on error. 1979 * 1980 * *sec* defines which SEC() definitions are handled by this custom handler 1981 * registration. *sec* can have few different forms: 1982 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1983 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1984 * in an error; 1985 * - if *sec* is of the form "abc/", proper SEC() form is 1986 * SEC("abc/something"), where acceptable "something" should be checked by 1987 * *prog_init_fn* callback, if there are additional restrictions; 1988 * - if *sec* is of the form "abc+", it will successfully match both 1989 * SEC("abc") and SEC("abc/whatever") forms; 1990 * - if *sec* is NULL, custom handler is registered for any BPF program that 1991 * doesn't match any of the registered (custom or libbpf's own) SEC() 1992 * handlers. There could be only one such generic custom handler registered 1993 * at any given time. 1994 * 1995 * All custom handlers (except the one with *sec* == NULL) are processed 1996 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1997 * SEC() handlers by registering custom ones for the same section prefix 1998 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1999 * handler). 2000 * 2001 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 2002 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 2003 * to ensure synchronization if there is a risk of running this API from 2004 * multiple threads simultaneously. 2005 */ 2006 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 2007 enum bpf_prog_type prog_type, 2008 enum bpf_attach_type exp_attach_type, 2009 const struct libbpf_prog_handler_opts *opts); 2010 /** 2011 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 2012 * custom BPF program SEC() handler. 2013 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 2014 * after successful registration 2015 * @return 0 on success, negative error code if handler isn't found 2016 * 2017 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 2018 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 2019 * to ensure synchronization if there is a risk of running this API from 2020 * multiple threads simultaneously. 2021 */ 2022 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 2023 2024 #ifdef __cplusplus 2025 } /* extern "C" */ 2026 #endif 2027 2028 #endif /* __LIBBPF_LIBBPF_H */ 2029