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 /* enforce unique match */ 556 bool unique_match; 557 size_t :0; 558 }; 559 560 #define bpf_kprobe_multi_opts__last_field unique_match 561 562 LIBBPF_API struct bpf_link * 563 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 564 const char *pattern, 565 const struct bpf_kprobe_multi_opts *opts); 566 567 struct bpf_uprobe_multi_opts { 568 /* size of this struct, for forward/backward compatibility */ 569 size_t sz; 570 /* array of function symbols to attach to */ 571 const char **syms; 572 /* array of function addresses to attach to */ 573 const unsigned long *offsets; 574 /* optional, array of associated ref counter offsets */ 575 const unsigned long *ref_ctr_offsets; 576 /* optional, array of associated BPF cookies */ 577 const __u64 *cookies; 578 /* number of elements in syms/addrs/cookies arrays */ 579 size_t cnt; 580 /* create return uprobes */ 581 bool retprobe; 582 /* create session kprobes */ 583 bool session; 584 size_t :0; 585 }; 586 587 #define bpf_uprobe_multi_opts__last_field session 588 589 /** 590 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program 591 * to multiple uprobes with uprobe_multi link. 592 * 593 * User can specify 2 mutually exclusive set of inputs: 594 * 595 * 1) use only path/func_pattern/pid arguments 596 * 597 * 2) use path/pid with allowed combinations of 598 * syms/offsets/ref_ctr_offsets/cookies/cnt 599 * 600 * - syms and offsets are mutually exclusive 601 * - ref_ctr_offsets and cookies are optional 602 * 603 * 604 * @param prog BPF program to attach 605 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 606 * -1 for all processes 607 * @param binary_path Path to binary 608 * @param func_pattern Regular expression to specify functions to attach 609 * BPF program to 610 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**) 611 * @return 0, on success; negative error code, otherwise 612 */ 613 LIBBPF_API struct bpf_link * 614 bpf_program__attach_uprobe_multi(const struct bpf_program *prog, 615 pid_t pid, 616 const char *binary_path, 617 const char *func_pattern, 618 const struct bpf_uprobe_multi_opts *opts); 619 620 struct bpf_ksyscall_opts { 621 /* size of this struct, for forward/backward compatibility */ 622 size_t sz; 623 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 624 __u64 bpf_cookie; 625 /* attach as return probe? */ 626 bool retprobe; 627 size_t :0; 628 }; 629 #define bpf_ksyscall_opts__last_field retprobe 630 631 /** 632 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program 633 * to kernel syscall handler of a specified syscall. Optionally it's possible 634 * to request to install retprobe that will be triggered at syscall exit. It's 635 * also possible to associate BPF cookie (though options). 636 * 637 * Libbpf automatically will determine correct full kernel function name, 638 * which depending on system architecture and kernel version/configuration 639 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will 640 * attach specified program using kprobe/kretprobe mechanism. 641 * 642 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative 643 * **SEC("ksyscall/<syscall>")** annotation of BPF programs. 644 * 645 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do 646 * not handle all the calling convention quirks for mmap(), clone() and compat 647 * syscalls. It also only attaches to "native" syscall interfaces. If host 648 * system supports compat syscalls or defines 32-bit syscalls in 64-bit 649 * kernel, such syscall interfaces won't be attached to by libbpf. 650 * 651 * These limitations may or may not change in the future. Therefore it is 652 * recommended to use SEC("kprobe") for these syscalls or if working with 653 * compat and 32-bit interfaces is required. 654 * 655 * @param prog BPF program to attach 656 * @param syscall_name Symbolic name of the syscall (e.g., "bpf") 657 * @param opts Additional options (see **struct bpf_ksyscall_opts**) 658 * @return Reference to the newly created BPF link; or NULL is returned on 659 * error, error code is stored in errno 660 */ 661 LIBBPF_API struct bpf_link * 662 bpf_program__attach_ksyscall(const struct bpf_program *prog, 663 const char *syscall_name, 664 const struct bpf_ksyscall_opts *opts); 665 666 struct bpf_uprobe_opts { 667 /* size of this struct, for forward/backward compatibility */ 668 size_t sz; 669 /* offset of kernel reference counted USDT semaphore, added in 670 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 671 */ 672 size_t ref_ctr_offset; 673 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 674 __u64 bpf_cookie; 675 /* uprobe is return probe, invoked at function return time */ 676 bool retprobe; 677 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 678 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 679 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 680 * offset within a function, specify func_name and use func_offset argument to specify 681 * offset within the function. Shared library functions must specify the shared library 682 * binary_path. 683 */ 684 const char *func_name; 685 /* uprobe attach mode */ 686 enum probe_attach_mode attach_mode; 687 size_t :0; 688 }; 689 #define bpf_uprobe_opts__last_field attach_mode 690 691 /** 692 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 693 * to the userspace function which is found by binary path and 694 * offset. You can optionally specify a particular process to attach 695 * to. You can also optionally attach the program to the function 696 * exit instead of entry. 697 * 698 * @param prog BPF program to attach 699 * @param retprobe Attach to function exit 700 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 701 * -1 for all processes 702 * @param binary_path Path to binary that contains the function symbol 703 * @param func_offset Offset within the binary of the function symbol 704 * @return Reference to the newly created BPF link; or NULL is returned on error, 705 * error code is stored in errno 706 */ 707 LIBBPF_API struct bpf_link * 708 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 709 pid_t pid, const char *binary_path, 710 size_t func_offset); 711 712 /** 713 * @brief **bpf_program__attach_uprobe_opts()** is just like 714 * bpf_program__attach_uprobe() except with a options struct 715 * for various configurations. 716 * 717 * @param prog BPF program to attach 718 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 719 * -1 for all processes 720 * @param binary_path Path to binary that contains the function symbol 721 * @param func_offset Offset within the binary of the function symbol 722 * @param opts Options for altering program attachment 723 * @return Reference to the newly created BPF link; or NULL is returned on error, 724 * error code is stored in errno 725 */ 726 LIBBPF_API struct bpf_link * 727 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 728 const char *binary_path, size_t func_offset, 729 const struct bpf_uprobe_opts *opts); 730 731 struct bpf_usdt_opts { 732 /* size of this struct, for forward/backward compatibility */ 733 size_t sz; 734 /* custom user-provided value accessible through usdt_cookie() */ 735 __u64 usdt_cookie; 736 size_t :0; 737 }; 738 #define bpf_usdt_opts__last_field usdt_cookie 739 740 /** 741 * @brief **bpf_program__attach_usdt()** is just like 742 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 743 * Statically Defined Tracepoint) attachment, instead of attaching to 744 * user-space function entry or exit. 745 * 746 * @param prog BPF program to attach 747 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 748 * -1 for all processes 749 * @param binary_path Path to binary that contains provided USDT probe 750 * @param usdt_provider USDT provider name 751 * @param usdt_name USDT probe name 752 * @param opts Options for altering program attachment 753 * @return Reference to the newly created BPF link; or NULL is returned on error, 754 * error code is stored in errno 755 */ 756 LIBBPF_API struct bpf_link * 757 bpf_program__attach_usdt(const struct bpf_program *prog, 758 pid_t pid, const char *binary_path, 759 const char *usdt_provider, const char *usdt_name, 760 const struct bpf_usdt_opts *opts); 761 762 struct bpf_tracepoint_opts { 763 /* size of this struct, for forward/backward compatibility */ 764 size_t sz; 765 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 766 __u64 bpf_cookie; 767 }; 768 #define bpf_tracepoint_opts__last_field bpf_cookie 769 770 LIBBPF_API struct bpf_link * 771 bpf_program__attach_tracepoint(const struct bpf_program *prog, 772 const char *tp_category, 773 const char *tp_name); 774 LIBBPF_API struct bpf_link * 775 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 776 const char *tp_category, 777 const char *tp_name, 778 const struct bpf_tracepoint_opts *opts); 779 780 struct bpf_raw_tracepoint_opts { 781 size_t sz; /* size of this struct for forward/backward compatibility */ 782 __u64 cookie; 783 size_t :0; 784 }; 785 #define bpf_raw_tracepoint_opts__last_field cookie 786 787 LIBBPF_API struct bpf_link * 788 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 789 const char *tp_name); 790 LIBBPF_API struct bpf_link * 791 bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog, 792 const char *tp_name, 793 struct bpf_raw_tracepoint_opts *opts); 794 795 struct bpf_trace_opts { 796 /* size of this struct, for forward/backward compatibility */ 797 size_t sz; 798 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 799 __u64 cookie; 800 }; 801 #define bpf_trace_opts__last_field cookie 802 803 LIBBPF_API struct bpf_link * 804 bpf_program__attach_trace(const struct bpf_program *prog); 805 LIBBPF_API struct bpf_link * 806 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 807 808 LIBBPF_API struct bpf_link * 809 bpf_program__attach_lsm(const struct bpf_program *prog); 810 LIBBPF_API struct bpf_link * 811 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 812 LIBBPF_API struct bpf_link * 813 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 814 LIBBPF_API struct bpf_link * 815 bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd); 816 LIBBPF_API struct bpf_link * 817 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 818 LIBBPF_API struct bpf_link * 819 bpf_program__attach_freplace(const struct bpf_program *prog, 820 int target_fd, const char *attach_func_name); 821 822 struct bpf_netfilter_opts { 823 /* size of this struct, for forward/backward compatibility */ 824 size_t sz; 825 826 __u32 pf; 827 __u32 hooknum; 828 __s32 priority; 829 __u32 flags; 830 }; 831 #define bpf_netfilter_opts__last_field flags 832 833 LIBBPF_API struct bpf_link * 834 bpf_program__attach_netfilter(const struct bpf_program *prog, 835 const struct bpf_netfilter_opts *opts); 836 837 struct bpf_tcx_opts { 838 /* size of this struct, for forward/backward compatibility */ 839 size_t sz; 840 __u32 flags; 841 __u32 relative_fd; 842 __u32 relative_id; 843 __u64 expected_revision; 844 size_t :0; 845 }; 846 #define bpf_tcx_opts__last_field expected_revision 847 848 LIBBPF_API struct bpf_link * 849 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, 850 const struct bpf_tcx_opts *opts); 851 852 struct bpf_netkit_opts { 853 /* size of this struct, for forward/backward compatibility */ 854 size_t sz; 855 __u32 flags; 856 __u32 relative_fd; 857 __u32 relative_id; 858 __u64 expected_revision; 859 size_t :0; 860 }; 861 #define bpf_netkit_opts__last_field expected_revision 862 863 LIBBPF_API struct bpf_link * 864 bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex, 865 const struct bpf_netkit_opts *opts); 866 867 struct bpf_map; 868 869 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 870 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); 871 872 struct bpf_iter_attach_opts { 873 size_t sz; /* size of this struct for forward/backward compatibility */ 874 union bpf_iter_link_info *link_info; 875 __u32 link_info_len; 876 }; 877 #define bpf_iter_attach_opts__last_field link_info_len 878 879 LIBBPF_API struct bpf_link * 880 bpf_program__attach_iter(const struct bpf_program *prog, 881 const struct bpf_iter_attach_opts *opts); 882 883 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 884 885 /** 886 * @brief **bpf_program__set_type()** sets the program 887 * type of the passed BPF program. 888 * @param prog BPF program to set the program type for 889 * @param type program type to set the BPF map to have 890 * @return error code; or 0 if no error. An error occurs 891 * if the object is already loaded. 892 * 893 * This must be called before the BPF object is loaded, 894 * otherwise it has no effect and an error is returned. 895 */ 896 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 897 enum bpf_prog_type type); 898 899 LIBBPF_API enum bpf_attach_type 900 bpf_program__expected_attach_type(const struct bpf_program *prog); 901 902 /** 903 * @brief **bpf_program__set_expected_attach_type()** sets the 904 * attach type of the passed BPF program. This is used for 905 * auto-detection of attachment when programs are loaded. 906 * @param prog BPF program to set the attach type for 907 * @param type attach type to set the BPF map to have 908 * @return error code; or 0 if no error. An error occurs 909 * if the object is already loaded. 910 * 911 * This must be called before the BPF object is loaded, 912 * otherwise it has no effect and an error is returned. 913 */ 914 LIBBPF_API int 915 bpf_program__set_expected_attach_type(struct bpf_program *prog, 916 enum bpf_attach_type type); 917 918 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 919 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 920 921 /* Per-program log level and log buffer getters/setters. 922 * See bpf_object_open_opts comments regarding log_level and log_buf 923 * interactions. 924 */ 925 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 926 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 927 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 928 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 929 930 /** 931 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 932 * for supported BPF program types: 933 * - BTF-aware raw tracepoints (tp_btf); 934 * - fentry/fexit/fmod_ret; 935 * - lsm; 936 * - freplace. 937 * @param prog BPF program to set the attach type for 938 * @param type attach type to set the BPF map to have 939 * @return error code; or 0 if no error occurred. 940 */ 941 LIBBPF_API int 942 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 943 const char *attach_func_name); 944 945 /** 946 * @brief **bpf_object__find_map_by_name()** returns BPF map of 947 * the given name, if it exists within the passed BPF object 948 * @param obj BPF object 949 * @param name name of the BPF map 950 * @return BPF map instance, if such map exists within the BPF object; 951 * or NULL otherwise. 952 */ 953 LIBBPF_API struct bpf_map * 954 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 955 956 LIBBPF_API int 957 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 958 959 LIBBPF_API struct bpf_map * 960 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 961 962 #define bpf_object__for_each_map(pos, obj) \ 963 for ((pos) = bpf_object__next_map((obj), NULL); \ 964 (pos) != NULL; \ 965 (pos) = bpf_object__next_map((obj), (pos))) 966 #define bpf_map__for_each bpf_object__for_each_map 967 968 LIBBPF_API struct bpf_map * 969 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 970 971 /** 972 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 973 * BPF map during BPF object load phase. 974 * @param map the BPF map instance 975 * @param autocreate whether to create BPF map during BPF object load 976 * @return 0 on success; -EBUSY if BPF object was already loaded 977 * 978 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 979 * BPF map. By default, libbpf will attempt to create every single BPF map 980 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 981 * and fill in map FD in BPF instructions. 982 * 983 * This API allows to opt-out of this process for specific map instance. This 984 * can be useful if host kernel doesn't support such BPF map type or used 985 * combination of flags and user application wants to avoid creating such 986 * a map in the first place. User is still responsible to make sure that their 987 * BPF-side code that expects to use such missing BPF map is recognized by BPF 988 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 989 */ 990 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 991 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 992 993 /** 994 * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach 995 * map during BPF skeleton attach phase. 996 * @param map the BPF map instance 997 * @param autoattach whether to attach map during BPF skeleton attach phase 998 * @return 0 on success; negative error code, otherwise 999 */ 1000 LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach); 1001 1002 /** 1003 * @brief **bpf_map__autoattach()** returns whether BPF map is configured to 1004 * auto-attach during BPF skeleton attach phase. 1005 * @param map the BPF map instance 1006 * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise 1007 */ 1008 LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map); 1009 1010 /** 1011 * @brief **bpf_map__fd()** gets the file descriptor of the passed 1012 * BPF map 1013 * @param map the BPF map instance 1014 * @return the file descriptor; or -EINVAL in case of an error 1015 */ 1016 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 1017 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 1018 /* get map name */ 1019 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 1020 /* get/set map type */ 1021 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 1022 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 1023 /* get/set map size (max_entries) */ 1024 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 1025 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 1026 /* get/set map flags */ 1027 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 1028 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 1029 /* get/set map NUMA node */ 1030 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 1031 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 1032 /* get/set map key size */ 1033 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 1034 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 1035 /* get map value size */ 1036 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 1037 /** 1038 * @brief **bpf_map__set_value_size()** sets map value size. 1039 * @param map the BPF map instance 1040 * @return 0, on success; negative error, otherwise 1041 * 1042 * There is a special case for maps with associated memory-mapped regions, like 1043 * the global data section maps (bss, data, rodata). When this function is used 1044 * on such a map, the mapped region is resized. Afterward, an attempt is made to 1045 * adjust the corresponding BTF info. This attempt is best-effort and can only 1046 * succeed if the last variable of the data section map is an array. The array 1047 * BTF type is replaced by a new BTF array type with a different length. 1048 * Any previously existing pointers returned from bpf_map__initial_value() or 1049 * corresponding data section skeleton pointer must be reinitialized. 1050 */ 1051 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 1052 /* get map key/value BTF type IDs */ 1053 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 1054 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 1055 /* get/set map if_index */ 1056 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 1057 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 1058 /* get/set map map_extra flags */ 1059 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 1060 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 1061 1062 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 1063 const void *data, size_t size); 1064 LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize); 1065 1066 /** 1067 * @brief **bpf_map__is_internal()** tells the caller whether or not the 1068 * passed map is a special map created by libbpf automatically for things like 1069 * global variables, __ksym externs, Kconfig values, etc 1070 * @param map the bpf_map 1071 * @return true, if the map is an internal map; false, otherwise 1072 */ 1073 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 1074 1075 /** 1076 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the 1077 * BPF map should be pinned. This does not actually create the 'pin'. 1078 * @param map The bpf_map 1079 * @param path The path 1080 * @return 0, on success; negative error, otherwise 1081 */ 1082 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 1083 1084 /** 1085 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the 1086 * BPF map should be pinned. 1087 * @param map The bpf_map 1088 * @return The path string; which can be NULL 1089 */ 1090 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 1091 1092 /** 1093 * @brief **bpf_map__is_pinned()** tells the caller whether or not the 1094 * passed map has been pinned via a 'pin' file. 1095 * @param map The bpf_map 1096 * @return true, if the map is pinned; false, otherwise 1097 */ 1098 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 1099 1100 /** 1101 * @brief **bpf_map__pin()** creates a file that serves as a 'pin' 1102 * for the BPF map. This increments the reference count on the 1103 * BPF map which will keep the BPF map loaded even after the 1104 * userspace process which loaded it has exited. 1105 * @param map The bpf_map to pin 1106 * @param path A file path for the 'pin' 1107 * @return 0, on success; negative error, otherwise 1108 * 1109 * If `path` is NULL the maps `pin_path` attribute will be used. If this is 1110 * also NULL, an error will be returned and the map will not be pinned. 1111 */ 1112 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 1113 1114 /** 1115 * @brief **bpf_map__unpin()** removes the file that serves as a 1116 * 'pin' for the BPF map. 1117 * @param map The bpf_map to unpin 1118 * @param path A file path for the 'pin' 1119 * @return 0, on success; negative error, otherwise 1120 * 1121 * The `path` parameter can be NULL, in which case the `pin_path` 1122 * map attribute is unpinned. If both the `path` parameter and 1123 * `pin_path` map attribute are set, they must be equal. 1124 */ 1125 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 1126 1127 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 1128 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 1129 1130 /** 1131 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 1132 * corresponding to provided key. 1133 * @param map BPF map to lookup element in 1134 * @param key pointer to memory containing bytes of the key used for lookup 1135 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1136 * @param value pointer to memory in which looked up value will be stored 1137 * @param value_sz size in byte of value data memory; it has to match BPF map 1138 * definition's **value_size**. For per-CPU BPF maps value size has to be 1139 * a product of BPF map value size and number of possible CPUs in the system 1140 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1141 * per-CPU values value size has to be aligned up to closest 8 bytes for 1142 * alignment reasons, so expected size is: `round_up(value_size, 8) 1143 * * libbpf_num_possible_cpus()`. 1144 * @flags extra flags passed to kernel for this operation 1145 * @return 0, on success; negative error, otherwise 1146 * 1147 * **bpf_map__lookup_elem()** is high-level equivalent of 1148 * **bpf_map_lookup_elem()** API with added check for key and value size. 1149 */ 1150 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 1151 const void *key, size_t key_sz, 1152 void *value, size_t value_sz, __u64 flags); 1153 1154 /** 1155 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 1156 * map that corresponds to provided key. 1157 * @param map BPF map to insert to or update element in 1158 * @param key pointer to memory containing bytes of the key 1159 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1160 * @param value pointer to memory containing bytes of the value 1161 * @param value_sz size in byte of value data memory; it has to match BPF map 1162 * definition's **value_size**. For per-CPU BPF maps value size has to be 1163 * a product of BPF map value size and number of possible CPUs in the system 1164 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1165 * per-CPU values value size has to be aligned up to closest 8 bytes for 1166 * alignment reasons, so expected size is: `round_up(value_size, 8) 1167 * * libbpf_num_possible_cpus()`. 1168 * @flags extra flags passed to kernel for this operation 1169 * @return 0, on success; negative error, otherwise 1170 * 1171 * **bpf_map__update_elem()** is high-level equivalent of 1172 * **bpf_map_update_elem()** API with added check for key and value size. 1173 */ 1174 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 1175 const void *key, size_t key_sz, 1176 const void *value, size_t value_sz, __u64 flags); 1177 1178 /** 1179 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 1180 * corresponds to provided key. 1181 * @param map BPF map to delete element from 1182 * @param key pointer to memory containing bytes of the key 1183 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1184 * @flags extra flags passed to kernel for this operation 1185 * @return 0, on success; negative error, otherwise 1186 * 1187 * **bpf_map__delete_elem()** is high-level equivalent of 1188 * **bpf_map_delete_elem()** API with added check for key size. 1189 */ 1190 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 1191 const void *key, size_t key_sz, __u64 flags); 1192 1193 /** 1194 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 1195 * corresponding to provided key and atomically delete it afterwards. 1196 * @param map BPF map to lookup element in 1197 * @param key pointer to memory containing bytes of the key used for lookup 1198 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1199 * @param value pointer to memory in which looked up value will be stored 1200 * @param value_sz size in byte of value data memory; it has to match BPF map 1201 * definition's **value_size**. For per-CPU BPF maps value size has to be 1202 * a product of BPF map value size and number of possible CPUs in the system 1203 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1204 * per-CPU values value size has to be aligned up to closest 8 bytes for 1205 * alignment reasons, so expected size is: `round_up(value_size, 8) 1206 * * libbpf_num_possible_cpus()`. 1207 * @flags extra flags passed to kernel for this operation 1208 * @return 0, on success; negative error, otherwise 1209 * 1210 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 1211 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 1212 */ 1213 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 1214 const void *key, size_t key_sz, 1215 void *value, size_t value_sz, __u64 flags); 1216 1217 /** 1218 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 1219 * fetching next key that follows current key. 1220 * @param map BPF map to fetch next key from 1221 * @param cur_key pointer to memory containing bytes of current key or NULL to 1222 * fetch the first key 1223 * @param next_key pointer to memory to write next key into 1224 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1225 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 1226 * negative error, otherwise 1227 * 1228 * **bpf_map__get_next_key()** is high-level equivalent of 1229 * **bpf_map_get_next_key()** API with added check for key size. 1230 */ 1231 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 1232 const void *cur_key, void *next_key, size_t key_sz); 1233 1234 struct bpf_xdp_set_link_opts { 1235 size_t sz; 1236 int old_fd; 1237 size_t :0; 1238 }; 1239 #define bpf_xdp_set_link_opts__last_field old_fd 1240 1241 struct bpf_xdp_attach_opts { 1242 size_t sz; 1243 int old_prog_fd; 1244 size_t :0; 1245 }; 1246 #define bpf_xdp_attach_opts__last_field old_prog_fd 1247 1248 struct bpf_xdp_query_opts { 1249 size_t sz; 1250 __u32 prog_id; /* output */ 1251 __u32 drv_prog_id; /* output */ 1252 __u32 hw_prog_id; /* output */ 1253 __u32 skb_prog_id; /* output */ 1254 __u8 attach_mode; /* output */ 1255 __u64 feature_flags; /* output */ 1256 __u32 xdp_zc_max_segs; /* output */ 1257 size_t :0; 1258 }; 1259 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs 1260 1261 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 1262 const struct bpf_xdp_attach_opts *opts); 1263 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 1264 const struct bpf_xdp_attach_opts *opts); 1265 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 1266 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 1267 1268 /* TC related API */ 1269 enum bpf_tc_attach_point { 1270 BPF_TC_INGRESS = 1 << 0, 1271 BPF_TC_EGRESS = 1 << 1, 1272 BPF_TC_CUSTOM = 1 << 2, 1273 }; 1274 1275 #define BPF_TC_PARENT(a, b) \ 1276 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 1277 1278 enum bpf_tc_flags { 1279 BPF_TC_F_REPLACE = 1 << 0, 1280 }; 1281 1282 struct bpf_tc_hook { 1283 size_t sz; 1284 int ifindex; 1285 enum bpf_tc_attach_point attach_point; 1286 __u32 parent; 1287 size_t :0; 1288 }; 1289 #define bpf_tc_hook__last_field parent 1290 1291 struct bpf_tc_opts { 1292 size_t sz; 1293 int prog_fd; 1294 __u32 flags; 1295 __u32 prog_id; 1296 __u32 handle; 1297 __u32 priority; 1298 size_t :0; 1299 }; 1300 #define bpf_tc_opts__last_field priority 1301 1302 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 1303 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 1304 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 1305 struct bpf_tc_opts *opts); 1306 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 1307 const struct bpf_tc_opts *opts); 1308 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 1309 struct bpf_tc_opts *opts); 1310 1311 /* Ring buffer APIs */ 1312 struct ring_buffer; 1313 struct ring; 1314 struct user_ring_buffer; 1315 1316 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 1317 1318 struct ring_buffer_opts { 1319 size_t sz; /* size of this struct, for forward/backward compatibility */ 1320 }; 1321 1322 #define ring_buffer_opts__last_field sz 1323 1324 LIBBPF_API struct ring_buffer * 1325 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 1326 const struct ring_buffer_opts *opts); 1327 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 1328 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 1329 ring_buffer_sample_fn sample_cb, void *ctx); 1330 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 1331 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 1332 LIBBPF_API int ring_buffer__consume_n(struct ring_buffer *rb, size_t n); 1333 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 1334 1335 /** 1336 * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given 1337 * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance. 1338 * 1339 * @param rb A ringbuffer manager object. 1340 * @param idx An index into the ringbuffers contained within the ringbuffer 1341 * manager object. The index is 0-based and corresponds to the order in which 1342 * ring_buffer__add was called. 1343 * @return A ringbuffer object on success; NULL and errno set if the index is 1344 * invalid. 1345 */ 1346 LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb, 1347 unsigned int idx); 1348 1349 /** 1350 * @brief **ring__consumer_pos()** returns the current consumer position in the 1351 * given ringbuffer. 1352 * 1353 * @param r A ringbuffer object. 1354 * @return The current consumer position. 1355 */ 1356 LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r); 1357 1358 /** 1359 * @brief **ring__producer_pos()** returns the current producer position in the 1360 * given ringbuffer. 1361 * 1362 * @param r A ringbuffer object. 1363 * @return The current producer position. 1364 */ 1365 LIBBPF_API unsigned long ring__producer_pos(const struct ring *r); 1366 1367 /** 1368 * @brief **ring__avail_data_size()** returns the number of bytes in the 1369 * ringbuffer not yet consumed. This has no locking associated with it, so it 1370 * can be inaccurate if operations are ongoing while this is called. However, it 1371 * should still show the correct trend over the long-term. 1372 * 1373 * @param r A ringbuffer object. 1374 * @return The number of bytes not yet consumed. 1375 */ 1376 LIBBPF_API size_t ring__avail_data_size(const struct ring *r); 1377 1378 /** 1379 * @brief **ring__size()** returns the total size of the ringbuffer's map data 1380 * area (excluding special producer/consumer pages). Effectively this gives the 1381 * amount of usable bytes of data inside the ringbuffer. 1382 * 1383 * @param r A ringbuffer object. 1384 * @return The total size of the ringbuffer map data area. 1385 */ 1386 LIBBPF_API size_t ring__size(const struct ring *r); 1387 1388 /** 1389 * @brief **ring__map_fd()** returns the file descriptor underlying the given 1390 * ringbuffer. 1391 * 1392 * @param r A ringbuffer object. 1393 * @return The underlying ringbuffer file descriptor 1394 */ 1395 LIBBPF_API int ring__map_fd(const struct ring *r); 1396 1397 /** 1398 * @brief **ring__consume()** consumes available ringbuffer data without event 1399 * polling. 1400 * 1401 * @param r A ringbuffer object. 1402 * @return The number of records consumed (or INT_MAX, whichever is less), or 1403 * a negative number if any of the callbacks return an error. 1404 */ 1405 LIBBPF_API int ring__consume(struct ring *r); 1406 1407 /** 1408 * @brief **ring__consume_n()** consumes up to a requested amount of items from 1409 * a ringbuffer without event polling. 1410 * 1411 * @param r A ringbuffer object. 1412 * @param n Maximum amount of items to consume. 1413 * @return The number of items consumed, or a negative number if any of the 1414 * callbacks return an error. 1415 */ 1416 LIBBPF_API int ring__consume_n(struct ring *r, size_t n); 1417 1418 struct user_ring_buffer_opts { 1419 size_t sz; /* size of this struct, for forward/backward compatibility */ 1420 }; 1421 1422 #define user_ring_buffer_opts__last_field sz 1423 1424 /** 1425 * @brief **user_ring_buffer__new()** creates a new instance of a user ring 1426 * buffer. 1427 * 1428 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map. 1429 * @param opts Options for how the ring buffer should be created. 1430 * @return A user ring buffer on success; NULL and errno being set on a 1431 * failure. 1432 */ 1433 LIBBPF_API struct user_ring_buffer * 1434 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); 1435 1436 /** 1437 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the 1438 * user ring buffer. 1439 * @param rb A pointer to a user ring buffer. 1440 * @param size The size of the sample, in bytes. 1441 * @return A pointer to an 8-byte aligned reserved region of the user ring 1442 * buffer; NULL, and errno being set if a sample could not be reserved. 1443 * 1444 * This function is *not* thread safe, and callers must synchronize accessing 1445 * this function if there are multiple producers. If a size is requested that 1446 * is larger than the size of the entire ring buffer, errno will be set to 1447 * E2BIG and NULL is returned. If the ring buffer could accommodate the size, 1448 * but currently does not have enough space, errno is set to ENOSPC and NULL is 1449 * returned. 1450 * 1451 * After initializing the sample, callers must invoke 1452 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise, 1453 * the sample must be freed with **user_ring_buffer__discard()**. 1454 */ 1455 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); 1456 1457 /** 1458 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the 1459 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes 1460 * available. 1461 * @param rb The user ring buffer. 1462 * @param size The size of the sample, in bytes. 1463 * @param timeout_ms The amount of time, in milliseconds, for which the caller 1464 * should block when waiting for a sample. -1 causes the caller to block 1465 * indefinitely. 1466 * @return A pointer to an 8-byte aligned reserved region of the user ring 1467 * buffer; NULL, and errno being set if a sample could not be reserved. 1468 * 1469 * This function is *not* thread safe, and callers must synchronize 1470 * accessing this function if there are multiple producers 1471 * 1472 * If **timeout_ms** is -1, the function will block indefinitely until a sample 1473 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno 1474 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking 1475 * will occur and the function will return immediately after attempting to 1476 * reserve a sample. 1477 * 1478 * If **size** is larger than the size of the entire ring buffer, errno is set 1479 * to E2BIG and NULL is returned. If the ring buffer could accommodate 1480 * **size**, but currently does not have enough space, the caller will block 1481 * until at most **timeout_ms** has elapsed. If insufficient space is available 1482 * at that time, errno is set to ENOSPC, and NULL is returned. 1483 * 1484 * The kernel guarantees that it will wake up this thread to check if 1485 * sufficient space is available in the ring buffer at least once per 1486 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at 1487 * least one sample is consumed, and the BPF program did not invoke the 1488 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the 1489 * kernel does not guarantee this. If the helper function is invoked with 1490 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is 1491 * consumed. 1492 * 1493 * When a sample of size **size** is found within **timeout_ms**, a pointer to 1494 * the sample is returned. After initializing the sample, callers must invoke 1495 * **user_ring_buffer__submit()** to post the sample to the ring buffer. 1496 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**. 1497 */ 1498 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, 1499 __u32 size, 1500 int timeout_ms); 1501 1502 /** 1503 * @brief **user_ring_buffer__submit()** submits a previously reserved sample 1504 * into the ring buffer. 1505 * @param rb The user ring buffer. 1506 * @param sample A reserved sample. 1507 * 1508 * It is not necessary to synchronize amongst multiple producers when invoking 1509 * this function. 1510 */ 1511 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); 1512 1513 /** 1514 * @brief **user_ring_buffer__discard()** discards a previously reserved sample. 1515 * @param rb The user ring buffer. 1516 * @param sample A reserved sample. 1517 * 1518 * It is not necessary to synchronize amongst multiple producers when invoking 1519 * this function. 1520 */ 1521 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample); 1522 1523 /** 1524 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously 1525 * created with **user_ring_buffer__new()**. 1526 * @param rb The user ring buffer being freed. 1527 */ 1528 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb); 1529 1530 /* Perf buffer APIs */ 1531 struct perf_buffer; 1532 1533 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 1534 void *data, __u32 size); 1535 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 1536 1537 /* common use perf buffer options */ 1538 struct perf_buffer_opts { 1539 size_t sz; 1540 __u32 sample_period; 1541 size_t :0; 1542 }; 1543 #define perf_buffer_opts__last_field sample_period 1544 1545 /** 1546 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1547 * BPF_PERF_EVENT_ARRAY map 1548 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1549 * code to send data over to user-space 1550 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1551 * @param sample_cb function called on each received data record 1552 * @param lost_cb function called when record loss has occurred 1553 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1554 * @return a new instance of struct perf_buffer on success, NULL on error with 1555 * *errno* containing an error code 1556 */ 1557 LIBBPF_API struct perf_buffer * 1558 perf_buffer__new(int map_fd, size_t page_cnt, 1559 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1560 const struct perf_buffer_opts *opts); 1561 1562 enum bpf_perf_event_ret { 1563 LIBBPF_PERF_EVENT_DONE = 0, 1564 LIBBPF_PERF_EVENT_ERROR = -1, 1565 LIBBPF_PERF_EVENT_CONT = -2, 1566 }; 1567 1568 struct perf_event_header; 1569 1570 typedef enum bpf_perf_event_ret 1571 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1572 1573 /* raw perf buffer options, giving most power and control */ 1574 struct perf_buffer_raw_opts { 1575 size_t sz; 1576 long :0; 1577 long :0; 1578 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1579 * max_entries of given PERF_EVENT_ARRAY map) 1580 */ 1581 int cpu_cnt; 1582 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1583 int *cpus; 1584 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1585 int *map_keys; 1586 }; 1587 #define perf_buffer_raw_opts__last_field map_keys 1588 1589 struct perf_event_attr; 1590 1591 LIBBPF_API struct perf_buffer * 1592 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1593 perf_buffer_event_fn event_cb, void *ctx, 1594 const struct perf_buffer_raw_opts *opts); 1595 1596 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1597 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1598 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1599 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1600 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1601 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1602 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1603 /** 1604 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying 1605 * memory region of the ring buffer. 1606 * This ring buffer can be used to implement a custom events consumer. 1607 * The ring buffer starts with the *struct perf_event_mmap_page*, which 1608 * holds the ring buffer management fields, when accessing the header 1609 * structure it's important to be SMP aware. 1610 * You can refer to *perf_event_read_simple* for a simple example. 1611 * @param pb the perf buffer structure 1612 * @param buf_idx the buffer index to retrieve 1613 * @param buf (out) gets the base pointer of the mmap()'ed memory 1614 * @param buf_size (out) gets the size of the mmap()'ed region 1615 * @return 0 on success, negative error code for failure 1616 */ 1617 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, 1618 size_t *buf_size); 1619 1620 struct bpf_prog_linfo; 1621 struct bpf_prog_info; 1622 1623 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1624 LIBBPF_API struct bpf_prog_linfo * 1625 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1626 LIBBPF_API const struct bpf_line_info * 1627 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1628 __u64 addr, __u32 func_idx, __u32 nr_skip); 1629 LIBBPF_API const struct bpf_line_info * 1630 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1631 __u32 insn_off, __u32 nr_skip); 1632 1633 /* 1634 * Probe for supported system features 1635 * 1636 * Note that running many of these probes in a short amount of time can cause 1637 * the kernel to reach the maximal size of lockable memory allowed for the 1638 * user, causing subsequent probes to fail. In this case, the caller may want 1639 * to adjust that limit with setrlimit(). 1640 */ 1641 1642 /** 1643 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1644 * BPF programs of a given type. 1645 * @param prog_type BPF program type to detect kernel support for 1646 * @param opts reserved for future extensibility, should be NULL 1647 * @return 1, if given program type is supported; 0, if given program type is 1648 * not supported; negative error code if feature detection failed or can't be 1649 * performed 1650 * 1651 * Make sure the process has required set of CAP_* permissions (or runs as 1652 * root) when performing feature checking. 1653 */ 1654 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1655 /** 1656 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1657 * BPF maps of a given type. 1658 * @param map_type BPF map type to detect kernel support for 1659 * @param opts reserved for future extensibility, should be NULL 1660 * @return 1, if given map type is supported; 0, if given map type is 1661 * not supported; negative error code if feature detection failed or can't be 1662 * performed 1663 * 1664 * Make sure the process has required set of CAP_* permissions (or runs as 1665 * root) when performing feature checking. 1666 */ 1667 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1668 /** 1669 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1670 * use of a given BPF helper from specified BPF program type. 1671 * @param prog_type BPF program type used to check the support of BPF helper 1672 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1673 * @param opts reserved for future extensibility, should be NULL 1674 * @return 1, if given combination of program type and helper is supported; 0, 1675 * if the combination is not supported; negative error code if feature 1676 * detection for provided input arguments failed or can't be performed 1677 * 1678 * Make sure the process has required set of CAP_* permissions (or runs as 1679 * root) when performing feature checking. 1680 */ 1681 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1682 enum bpf_func_id helper_id, const void *opts); 1683 1684 /** 1685 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1686 * number of possible CPUs that the host kernel supports and expects. 1687 * @return number of possible CPUs; or error code on failure 1688 * 1689 * Example usage: 1690 * 1691 * int ncpus = libbpf_num_possible_cpus(); 1692 * if (ncpus < 0) { 1693 * // error handling 1694 * } 1695 * long values[ncpus]; 1696 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1697 */ 1698 LIBBPF_API int libbpf_num_possible_cpus(void); 1699 1700 struct bpf_map_skeleton { 1701 const char *name; 1702 struct bpf_map **map; 1703 void **mmaped; 1704 struct bpf_link **link; 1705 }; 1706 1707 struct bpf_prog_skeleton { 1708 const char *name; 1709 struct bpf_program **prog; 1710 struct bpf_link **link; 1711 }; 1712 1713 struct bpf_object_skeleton { 1714 size_t sz; /* size of this struct, for forward/backward compatibility */ 1715 1716 const char *name; 1717 const void *data; 1718 size_t data_sz; 1719 1720 struct bpf_object **obj; 1721 1722 int map_cnt; 1723 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1724 struct bpf_map_skeleton *maps; 1725 1726 int prog_cnt; 1727 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1728 struct bpf_prog_skeleton *progs; 1729 }; 1730 1731 LIBBPF_API int 1732 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1733 const struct bpf_object_open_opts *opts); 1734 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1735 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1736 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1737 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1738 1739 struct bpf_var_skeleton { 1740 const char *name; 1741 struct bpf_map **map; 1742 void **addr; 1743 }; 1744 1745 struct bpf_object_subskeleton { 1746 size_t sz; /* size of this struct, for forward/backward compatibility */ 1747 1748 const struct bpf_object *obj; 1749 1750 int map_cnt; 1751 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1752 struct bpf_map_skeleton *maps; 1753 1754 int prog_cnt; 1755 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1756 struct bpf_prog_skeleton *progs; 1757 1758 int var_cnt; 1759 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1760 struct bpf_var_skeleton *vars; 1761 }; 1762 1763 LIBBPF_API int 1764 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1765 LIBBPF_API void 1766 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1767 1768 struct gen_loader_opts { 1769 size_t sz; /* size of this struct, for forward/backward compatibility */ 1770 const char *data; 1771 const char *insns; 1772 __u32 data_sz; 1773 __u32 insns_sz; 1774 }; 1775 1776 #define gen_loader_opts__last_field insns_sz 1777 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1778 struct gen_loader_opts *opts); 1779 1780 enum libbpf_tristate { 1781 TRI_NO = 0, 1782 TRI_YES = 1, 1783 TRI_MODULE = 2, 1784 }; 1785 1786 struct bpf_linker_opts { 1787 /* size of this struct, for forward/backward compatibility */ 1788 size_t sz; 1789 }; 1790 #define bpf_linker_opts__last_field sz 1791 1792 struct bpf_linker_file_opts { 1793 /* size of this struct, for forward/backward compatibility */ 1794 size_t sz; 1795 }; 1796 #define bpf_linker_file_opts__last_field sz 1797 1798 struct bpf_linker; 1799 1800 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1801 LIBBPF_API struct bpf_linker *bpf_linker__new_fd(int fd, struct bpf_linker_opts *opts); 1802 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1803 const char *filename, 1804 const struct bpf_linker_file_opts *opts); 1805 LIBBPF_API int bpf_linker__add_fd(struct bpf_linker *linker, int fd, 1806 const struct bpf_linker_file_opts *opts); 1807 LIBBPF_API int bpf_linker__add_buf(struct bpf_linker *linker, void *buf, size_t buf_sz, 1808 const struct bpf_linker_file_opts *opts); 1809 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1810 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1811 1812 /* 1813 * Custom handling of BPF program's SEC() definitions 1814 */ 1815 1816 struct bpf_prog_load_opts; /* defined in bpf.h */ 1817 1818 /* Called during bpf_object__open() for each recognized BPF program. Callback 1819 * can use various bpf_program__set_*() setters to adjust whatever properties 1820 * are necessary. 1821 */ 1822 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1823 1824 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1825 * into the kernel. Callback can adjust opts as necessary. 1826 */ 1827 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1828 struct bpf_prog_load_opts *opts, long cookie); 1829 1830 /* Called during skeleton attach or through bpf_program__attach(). If 1831 * auto-attach is not supported, callback should return 0 and set link to 1832 * NULL (it's not considered an error during skeleton attach, but it will be 1833 * an error for bpf_program__attach() calls). On error, error should be 1834 * returned directly and link set to NULL. On success, return 0 and set link 1835 * to a valid struct bpf_link. 1836 */ 1837 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1838 struct bpf_link **link); 1839 1840 struct libbpf_prog_handler_opts { 1841 /* size of this struct, for forward/backward compatibility */ 1842 size_t sz; 1843 /* User-provided value that is passed to prog_setup_fn, 1844 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1845 * register one set of callbacks for multiple SEC() definitions and 1846 * still be able to distinguish them, if necessary. For example, 1847 * libbpf itself is using this to pass necessary flags (e.g., 1848 * sleepable flag) to a common internal SEC() handler. 1849 */ 1850 long cookie; 1851 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1852 * Callback is optional, pass NULL if it's not necessary. 1853 */ 1854 libbpf_prog_setup_fn_t prog_setup_fn; 1855 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1856 * Callback is optional, pass NULL if it's not necessary. 1857 */ 1858 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1859 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1860 * Callback is optional, pass NULL if it's not necessary. 1861 */ 1862 libbpf_prog_attach_fn_t prog_attach_fn; 1863 }; 1864 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1865 1866 /** 1867 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1868 * SEC() handler. 1869 * @param sec section prefix for which custom handler is registered 1870 * @param prog_type BPF program type associated with specified section 1871 * @param exp_attach_type Expected BPF attach type associated with specified section 1872 * @param opts optional cookie, callbacks, and other extra options 1873 * @return Non-negative handler ID is returned on success. This handler ID has 1874 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1875 * custom handler. Negative error code is returned on error. 1876 * 1877 * *sec* defines which SEC() definitions are handled by this custom handler 1878 * registration. *sec* can have few different forms: 1879 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1880 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1881 * in an error; 1882 * - if *sec* is of the form "abc/", proper SEC() form is 1883 * SEC("abc/something"), where acceptable "something" should be checked by 1884 * *prog_init_fn* callback, if there are additional restrictions; 1885 * - if *sec* is of the form "abc+", it will successfully match both 1886 * SEC("abc") and SEC("abc/whatever") forms; 1887 * - if *sec* is NULL, custom handler is registered for any BPF program that 1888 * doesn't match any of the registered (custom or libbpf's own) SEC() 1889 * handlers. There could be only one such generic custom handler registered 1890 * at any given time. 1891 * 1892 * All custom handlers (except the one with *sec* == NULL) are processed 1893 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1894 * SEC() handlers by registering custom ones for the same section prefix 1895 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1896 * handler). 1897 * 1898 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1899 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1900 * to ensure synchronization if there is a risk of running this API from 1901 * multiple threads simultaneously. 1902 */ 1903 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 1904 enum bpf_prog_type prog_type, 1905 enum bpf_attach_type exp_attach_type, 1906 const struct libbpf_prog_handler_opts *opts); 1907 /** 1908 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 1909 * custom BPF program SEC() handler. 1910 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 1911 * after successful registration 1912 * @return 0 on success, negative error code if handler isn't found 1913 * 1914 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1915 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1916 * to ensure synchronization if there is a risk of running this API from 1917 * multiple threads simultaneously. 1918 */ 1919 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 1920 1921 #ifdef __cplusplus 1922 } /* extern "C" */ 1923 #endif 1924 1925 #endif /* __LIBBPF_LIBBPF_H */ 1926