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