1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 3 /* 4 * Common eBPF ELF object loading operations. 5 * 6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 8 * Copyright (C) 2015 Huawei Inc. 9 */ 10 #ifndef __LIBBPF_LIBBPF_H 11 #define __LIBBPF_LIBBPF_H 12 13 #include <stdarg.h> 14 #include <stdio.h> 15 #include <stdint.h> 16 #include <stdbool.h> 17 #include <sys/types.h> // for size_t 18 #include <linux/bpf.h> 19 20 #include "libbpf_common.h" 21 #include "libbpf_legacy.h" 22 23 #ifdef __cplusplus 24 extern "C" { 25 #endif 26 27 LIBBPF_API __u32 libbpf_major_version(void); 28 LIBBPF_API __u32 libbpf_minor_version(void); 29 LIBBPF_API const char *libbpf_version_string(void); 30 31 enum libbpf_errno { 32 __LIBBPF_ERRNO__START = 4000, 33 34 /* Something wrong in libelf */ 35 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 36 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 37 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 38 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 39 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 40 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 41 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 42 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 43 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 44 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 45 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 46 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 47 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 48 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 49 __LIBBPF_ERRNO__END, 50 }; 51 52 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 53 54 /** 55 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type 56 * value into a textual representation. 57 * @param t The attach type. 58 * @return Pointer to a static string identifying the attach type. NULL is 59 * returned for unknown **bpf_attach_type** values. 60 */ 61 LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t); 62 63 /** 64 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value 65 * into a textual representation. 66 * @param t The link type. 67 * @return Pointer to a static string identifying the link type. NULL is 68 * returned for unknown **bpf_link_type** values. 69 */ 70 LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t); 71 72 /** 73 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value 74 * into a textual representation. 75 * @param t The map type. 76 * @return Pointer to a static string identifying the map type. NULL is 77 * returned for unknown **bpf_map_type** values. 78 */ 79 LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t); 80 81 /** 82 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type 83 * value into a textual representation. 84 * @param t The program type. 85 * @return Pointer to a static string identifying the program type. NULL is 86 * returned for unknown **bpf_prog_type** values. 87 */ 88 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t); 89 90 enum libbpf_print_level { 91 LIBBPF_WARN, 92 LIBBPF_INFO, 93 LIBBPF_DEBUG, 94 }; 95 96 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, 97 const char *, va_list ap); 98 99 /** 100 * @brief **libbpf_set_print()** sets user-provided log callback function to 101 * be used for libbpf warnings and informational messages. 102 * @param fn The log print function. If NULL, libbpf won't print anything. 103 * @return Pointer to old print function. 104 * 105 * This function is thread-safe. 106 */ 107 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); 108 109 /* Hide internal to user */ 110 struct bpf_object; 111 112 struct bpf_object_open_opts { 113 /* size of this struct, for forward/backward compatibility */ 114 size_t sz; 115 /* object name override, if provided: 116 * - for object open from file, this will override setting object 117 * name from file path's base name; 118 * - for object open from memory buffer, this will specify an object 119 * name and will override default "<addr>-<buf-size>" name; 120 */ 121 const char *object_name; 122 /* parse map definitions non-strictly, allowing extra attributes/data */ 123 bool relaxed_maps; 124 /* maps that set the 'pinning' attribute in their definition will have 125 * their pin_path attribute set to a file in this directory, and be 126 * auto-pinned to that path on load; defaults to "/sys/fs/bpf". 127 */ 128 const char *pin_root_path; 129 130 __u32 :32; /* stub out now removed attach_prog_fd */ 131 132 /* Additional kernel config content that augments and overrides 133 * system Kconfig for CONFIG_xxx externs. 134 */ 135 const char *kconfig; 136 /* Path to the custom BTF to be used for BPF CO-RE relocations. 137 * This custom BTF completely replaces the use of vmlinux BTF 138 * for the purpose of CO-RE relocations. 139 * NOTE: any other BPF feature (e.g., fentry/fexit programs, 140 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. 141 */ 142 const char *btf_custom_path; 143 /* Pointer to a buffer for storing kernel logs for applicable BPF 144 * commands. Valid kernel_log_size has to be specified as well and are 145 * passed-through to bpf() syscall. Keep in mind that kernel might 146 * fail operation with -ENOSPC error if provided buffer is too small 147 * to contain entire log output. 148 * See the comment below for kernel_log_level for interaction between 149 * log_buf and log_level settings. 150 * 151 * If specified, this log buffer will be passed for: 152 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden 153 * with bpf_program__set_log() on per-program level, to get 154 * BPF verifier log output. 155 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get 156 * BTF sanity checking log. 157 * 158 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite 159 * previous contents, so if you need more fine-grained control, set 160 * per-program buffer with bpf_program__set_log_buf() to preserve each 161 * individual program's verification log. Keep using kernel_log_buf 162 * for BTF verification log, if necessary. 163 */ 164 char *kernel_log_buf; 165 size_t kernel_log_size; 166 /* 167 * Log level can be set independently from log buffer. Log_level=0 168 * means that libbpf will attempt loading BTF or program without any 169 * logging requested, but will retry with either its own or custom log 170 * buffer, if provided, and log_level=1 on any error. 171 * And vice versa, setting log_level>0 will request BTF or prog 172 * loading with verbose log from the first attempt (and as such also 173 * for successfully loaded BTF or program), and the actual log buffer 174 * could be either libbpf's own auto-allocated log buffer, if 175 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. 176 * If user didn't provide custom log buffer, libbpf will emit captured 177 * logs through its print callback. 178 */ 179 __u32 kernel_log_level; 180 181 size_t :0; 182 }; 183 #define bpf_object_open_opts__last_field kernel_log_level 184 185 /** 186 * @brief **bpf_object__open()** creates a bpf_object by opening 187 * the BPF ELF object file pointed to by the passed path and loading it 188 * into memory. 189 * @param path BPF object file path. 190 * @return pointer to the new bpf_object; or NULL is returned on error, 191 * error code is stored in errno 192 */ 193 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 194 195 /** 196 * @brief **bpf_object__open_file()** creates a bpf_object by opening 197 * the BPF ELF object file pointed to by the passed path and loading it 198 * into memory. 199 * @param path BPF object file path 200 * @param opts options for how to load the bpf object, this parameter is 201 * optional and can be set to NULL 202 * @return pointer to the new bpf_object; or NULL is returned on error, 203 * error code is stored in errno 204 */ 205 LIBBPF_API struct bpf_object * 206 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); 207 208 /** 209 * @brief **bpf_object__open_mem()** creates a bpf_object by reading 210 * the BPF objects raw bytes from a memory buffer containing a valid 211 * BPF ELF object file. 212 * @param obj_buf pointer to the buffer containing ELF file bytes 213 * @param obj_buf_sz number of bytes in the buffer 214 * @param opts options for how to load the bpf object 215 * @return pointer to the new bpf_object; or NULL is returned on error, 216 * error code is stored in errno 217 */ 218 LIBBPF_API struct bpf_object * 219 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, 220 const struct bpf_object_open_opts *opts); 221 222 /** 223 * @brief **bpf_object__load()** loads BPF object into kernel. 224 * @param obj Pointer to a valid BPF object instance returned by 225 * **bpf_object__open*()** APIs 226 * @return 0, on success; negative error code, otherwise, error code is 227 * stored in errno 228 */ 229 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 230 231 /** 232 * @brief **bpf_object__close()** closes a BPF object and releases all 233 * resources. 234 * @param obj Pointer to a valid BPF object 235 */ 236 LIBBPF_API void bpf_object__close(struct bpf_object *obj); 237 238 /** 239 * @brief **bpf_object__pin_maps()** pins each map contained within 240 * the BPF object at the passed directory. 241 * @param obj Pointer to a valid BPF object 242 * @param path A directory where maps should be pinned. 243 * @return 0, on success; negative error code, otherwise 244 * 245 * If `path` is NULL `bpf_map__pin` (which is being used on each map) 246 * will use the pin_path attribute of each map. In this case, maps that 247 * don't have a pin_path set will be ignored. 248 */ 249 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 250 251 /** 252 * @brief **bpf_object__unpin_maps()** unpins each map contained within 253 * the BPF object found in the passed directory. 254 * @param obj Pointer to a valid BPF object 255 * @param path A directory where pinned maps should be searched for. 256 * @return 0, on success; negative error code, otherwise 257 * 258 * If `path` is NULL `bpf_map__unpin` (which is being used on each map) 259 * will use the pin_path attribute of each map. In this case, maps that 260 * don't have a pin_path set will be ignored. 261 */ 262 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 263 const char *path); 264 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 265 const char *path); 266 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 267 const char *path); 268 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 269 LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path); 270 271 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); 272 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); 273 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); 274 275 struct btf; 276 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); 277 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 278 279 LIBBPF_API struct bpf_program * 280 bpf_object__find_program_by_name(const struct bpf_object *obj, 281 const char *name); 282 283 LIBBPF_API int 284 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 285 enum bpf_attach_type *expected_attach_type); 286 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 287 enum bpf_attach_type *attach_type); 288 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, 289 enum bpf_attach_type attach_type); 290 291 /* Accessors of bpf_program */ 292 struct bpf_program; 293 294 LIBBPF_API struct bpf_program * 295 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); 296 297 #define bpf_object__for_each_program(pos, obj) \ 298 for ((pos) = bpf_object__next_program((obj), NULL); \ 299 (pos) != NULL; \ 300 (pos) = bpf_object__next_program((obj), (pos))) 301 302 LIBBPF_API struct bpf_program * 303 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); 304 305 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 306 __u32 ifindex); 307 308 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); 309 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); 310 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); 311 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); 312 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog); 313 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach); 314 315 struct bpf_insn; 316 317 /** 318 * @brief **bpf_program__insns()** gives read-only access to BPF program's 319 * underlying BPF instructions. 320 * @param prog BPF program for which to return instructions 321 * @return a pointer to an array of BPF instructions that belong to the 322 * specified BPF program 323 * 324 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` 325 * pointed to can be fetched using **bpf_program__insn_cnt()** API. 326 * 327 * Keep in mind, libbpf can modify and append/delete BPF program's 328 * instructions as it processes BPF object file and prepares everything for 329 * uploading into the kernel. So depending on the point in BPF object 330 * lifetime, **bpf_program__insns()** can return different sets of 331 * instructions. As an example, during BPF object load phase BPF program 332 * instructions will be CO-RE-relocated, BPF subprograms instructions will be 333 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions 334 * returned before **bpf_object__load()** and after it might be quite 335 * different. 336 */ 337 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); 338 339 /** 340 * @brief **bpf_program__set_insns()** can set BPF program's underlying 341 * BPF instructions. 342 * 343 * WARNING: This is a very advanced libbpf API and users need to know 344 * what they are doing. This should be used from prog_prepare_load_fn 345 * callback only. 346 * 347 * @param prog BPF program for which to return instructions 348 * @param new_insns a pointer to an array of BPF instructions 349 * @param new_insn_cnt number of `struct bpf_insn`'s that form 350 * specified BPF program 351 * @return 0, on success; negative error code, otherwise 352 */ 353 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, 354 struct bpf_insn *new_insns, size_t new_insn_cnt); 355 356 /** 357 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s 358 * that form specified BPF program. 359 * @param prog BPF program for which to return number of BPF instructions 360 * 361 * See **bpf_program__insns()** documentation for notes on how libbpf can 362 * change instructions and their count during different phases of 363 * **bpf_object** lifetime. 364 */ 365 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); 366 367 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); 368 369 /** 370 * @brief **bpf_program__pin()** pins the BPF program to a file 371 * in the BPF FS specified by a path. This increments the programs 372 * reference count, allowing it to stay loaded after the process 373 * which loaded it has exited. 374 * 375 * @param prog BPF program to pin, must already be loaded 376 * @param path file path in a BPF file system 377 * @return 0, on success; negative error code, otherwise 378 */ 379 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 380 381 /** 382 * @brief **bpf_program__unpin()** unpins the BPF program from a file 383 * in the BPFFS specified by a path. This decrements the programs 384 * reference count. 385 * 386 * The file pinning the BPF program can also be unlinked by a different 387 * process in which case this function will return an error. 388 * 389 * @param prog BPF program to unpin 390 * @param path file path to the pin in a BPF file system 391 * @return 0, on success; negative error code, otherwise 392 */ 393 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 394 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 395 396 struct bpf_link; 397 398 LIBBPF_API struct bpf_link *bpf_link__open(const char *path); 399 LIBBPF_API int bpf_link__fd(const struct bpf_link *link); 400 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); 401 /** 402 * @brief **bpf_link__pin()** pins the BPF link to a file 403 * in the BPF FS specified by a path. This increments the links 404 * reference count, allowing it to stay loaded after the process 405 * which loaded it has exited. 406 * 407 * @param link BPF link to pin, must already be loaded 408 * @param path file path in a BPF file system 409 * @return 0, on success; negative error code, otherwise 410 */ 411 412 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); 413 414 /** 415 * @brief **bpf_link__unpin()** unpins the BPF link from a file 416 * in the BPFFS specified by a path. This decrements the links 417 * reference count. 418 * 419 * The file pinning the BPF link can also be unlinked by a different 420 * process in which case this function will return an error. 421 * 422 * @param prog BPF program to unpin 423 * @param path file path to the pin in a BPF file system 424 * @return 0, on success; negative error code, otherwise 425 */ 426 LIBBPF_API int bpf_link__unpin(struct bpf_link *link); 427 LIBBPF_API int bpf_link__update_program(struct bpf_link *link, 428 struct bpf_program *prog); 429 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); 430 LIBBPF_API int bpf_link__detach(struct bpf_link *link); 431 LIBBPF_API int bpf_link__destroy(struct bpf_link *link); 432 433 /** 434 * @brief **bpf_program__attach()** is a generic function for attaching 435 * a BPF program based on auto-detection of program type, attach type, 436 * and extra paremeters, where applicable. 437 * 438 * @param prog BPF program to attach 439 * @return Reference to the newly created BPF link; or NULL is returned on error, 440 * error code is stored in errno 441 * 442 * This is supported for: 443 * - kprobe/kretprobe (depends on SEC() definition) 444 * - uprobe/uretprobe (depends on SEC() definition) 445 * - tracepoint 446 * - raw tracepoint 447 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) 448 */ 449 LIBBPF_API struct bpf_link * 450 bpf_program__attach(const struct bpf_program *prog); 451 452 struct bpf_perf_event_opts { 453 /* size of this struct, for forward/backward compatibility */ 454 size_t sz; 455 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 456 __u64 bpf_cookie; 457 /* don't use BPF link when attach BPF program */ 458 bool force_ioctl_attach; 459 size_t :0; 460 }; 461 #define bpf_perf_event_opts__last_field force_ioctl_attach 462 463 LIBBPF_API struct bpf_link * 464 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); 465 466 LIBBPF_API struct bpf_link * 467 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, 468 const struct bpf_perf_event_opts *opts); 469 470 /** 471 * enum probe_attach_mode - the mode to attach kprobe/uprobe 472 * 473 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will 474 * be returned if it is not supported by the kernel. 475 */ 476 enum probe_attach_mode { 477 /* attach probe in latest supported mode by kernel */ 478 PROBE_ATTACH_MODE_DEFAULT = 0, 479 /* attach probe in legacy mode, using debugfs/tracefs */ 480 PROBE_ATTACH_MODE_LEGACY, 481 /* create perf event with perf_event_open() syscall */ 482 PROBE_ATTACH_MODE_PERF, 483 /* attach probe with BPF link */ 484 PROBE_ATTACH_MODE_LINK, 485 }; 486 487 struct bpf_kprobe_opts { 488 /* size of this struct, for forward/backward compatibility */ 489 size_t sz; 490 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 491 __u64 bpf_cookie; 492 /* function's offset to install kprobe to */ 493 size_t offset; 494 /* kprobe is return probe */ 495 bool retprobe; 496 /* kprobe attach mode */ 497 enum probe_attach_mode attach_mode; 498 size_t :0; 499 }; 500 #define bpf_kprobe_opts__last_field attach_mode 501 502 LIBBPF_API struct bpf_link * 503 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, 504 const char *func_name); 505 LIBBPF_API struct bpf_link * 506 bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 507 const char *func_name, 508 const struct bpf_kprobe_opts *opts); 509 510 struct bpf_kprobe_multi_opts { 511 /* size of this struct, for forward/backward compatibility */ 512 size_t sz; 513 /* array of function symbols to attach */ 514 const char **syms; 515 /* array of function addresses to attach */ 516 const unsigned long *addrs; 517 /* array of user-provided values fetchable through bpf_get_attach_cookie */ 518 const __u64 *cookies; 519 /* number of elements in syms/addrs/cookies arrays */ 520 size_t cnt; 521 /* create return kprobes */ 522 bool retprobe; 523 size_t :0; 524 }; 525 526 #define bpf_kprobe_multi_opts__last_field retprobe 527 528 LIBBPF_API struct bpf_link * 529 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 530 const char *pattern, 531 const struct bpf_kprobe_multi_opts *opts); 532 533 struct bpf_uprobe_multi_opts { 534 /* size of this struct, for forward/backward compatibility */ 535 size_t sz; 536 /* array of function symbols to attach to */ 537 const char **syms; 538 /* array of function addresses to attach to */ 539 const unsigned long *offsets; 540 /* optional, array of associated ref counter offsets */ 541 const unsigned long *ref_ctr_offsets; 542 /* optional, array of associated BPF cookies */ 543 const __u64 *cookies; 544 /* number of elements in syms/addrs/cookies arrays */ 545 size_t cnt; 546 /* create return uprobes */ 547 bool retprobe; 548 size_t :0; 549 }; 550 551 #define bpf_uprobe_multi_opts__last_field retprobe 552 553 /** 554 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program 555 * to multiple uprobes with uprobe_multi link. 556 * 557 * User can specify 2 mutually exclusive set of inputs: 558 * 559 * 1) use only path/func_pattern/pid arguments 560 * 561 * 2) use path/pid with allowed combinations of 562 * syms/offsets/ref_ctr_offsets/cookies/cnt 563 * 564 * - syms and offsets are mutually exclusive 565 * - ref_ctr_offsets and cookies are optional 566 * 567 * 568 * @param prog BPF program to attach 569 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 570 * -1 for all processes 571 * @param binary_path Path to binary 572 * @param func_pattern Regular expression to specify functions to attach 573 * BPF program to 574 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**) 575 * @return 0, on success; negative error code, otherwise 576 */ 577 LIBBPF_API struct bpf_link * 578 bpf_program__attach_uprobe_multi(const struct bpf_program *prog, 579 pid_t pid, 580 const char *binary_path, 581 const char *func_pattern, 582 const struct bpf_uprobe_multi_opts *opts); 583 584 struct bpf_ksyscall_opts { 585 /* size of this struct, for forward/backward compatibility */ 586 size_t sz; 587 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 588 __u64 bpf_cookie; 589 /* attach as return probe? */ 590 bool retprobe; 591 size_t :0; 592 }; 593 #define bpf_ksyscall_opts__last_field retprobe 594 595 /** 596 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program 597 * to kernel syscall handler of a specified syscall. Optionally it's possible 598 * to request to install retprobe that will be triggered at syscall exit. It's 599 * also possible to associate BPF cookie (though options). 600 * 601 * Libbpf automatically will determine correct full kernel function name, 602 * which depending on system architecture and kernel version/configuration 603 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will 604 * attach specified program using kprobe/kretprobe mechanism. 605 * 606 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative 607 * **SEC("ksyscall/<syscall>")** annotation of BPF programs. 608 * 609 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do 610 * not handle all the calling convention quirks for mmap(), clone() and compat 611 * syscalls. It also only attaches to "native" syscall interfaces. If host 612 * system supports compat syscalls or defines 32-bit syscalls in 64-bit 613 * kernel, such syscall interfaces won't be attached to by libbpf. 614 * 615 * These limitations may or may not change in the future. Therefore it is 616 * recommended to use SEC("kprobe") for these syscalls or if working with 617 * compat and 32-bit interfaces is required. 618 * 619 * @param prog BPF program to attach 620 * @param syscall_name Symbolic name of the syscall (e.g., "bpf") 621 * @param opts Additional options (see **struct bpf_ksyscall_opts**) 622 * @return Reference to the newly created BPF link; or NULL is returned on 623 * error, error code is stored in errno 624 */ 625 LIBBPF_API struct bpf_link * 626 bpf_program__attach_ksyscall(const struct bpf_program *prog, 627 const char *syscall_name, 628 const struct bpf_ksyscall_opts *opts); 629 630 struct bpf_uprobe_opts { 631 /* size of this struct, for forward/backward compatibility */ 632 size_t sz; 633 /* offset of kernel reference counted USDT semaphore, added in 634 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 635 */ 636 size_t ref_ctr_offset; 637 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 638 __u64 bpf_cookie; 639 /* uprobe is return probe, invoked at function return time */ 640 bool retprobe; 641 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 642 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 643 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 644 * offset within a function, specify func_name and use func_offset argument to specify 645 * offset within the function. Shared library functions must specify the shared library 646 * binary_path. 647 */ 648 const char *func_name; 649 /* uprobe attach mode */ 650 enum probe_attach_mode attach_mode; 651 size_t :0; 652 }; 653 #define bpf_uprobe_opts__last_field attach_mode 654 655 /** 656 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 657 * to the userspace function which is found by binary path and 658 * offset. You can optionally specify a particular proccess to attach 659 * to. You can also optionally attach the program to the function 660 * exit instead of entry. 661 * 662 * @param prog BPF program to attach 663 * @param retprobe Attach to function exit 664 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 665 * -1 for all processes 666 * @param binary_path Path to binary that contains the function symbol 667 * @param func_offset Offset within the binary of the function symbol 668 * @return Reference to the newly created BPF link; or NULL is returned on error, 669 * error code is stored in errno 670 */ 671 LIBBPF_API struct bpf_link * 672 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 673 pid_t pid, const char *binary_path, 674 size_t func_offset); 675 676 /** 677 * @brief **bpf_program__attach_uprobe_opts()** is just like 678 * bpf_program__attach_uprobe() except with a options struct 679 * for various configurations. 680 * 681 * @param prog BPF program to attach 682 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 683 * -1 for all processes 684 * @param binary_path Path to binary that contains the function symbol 685 * @param func_offset Offset within the binary of the function symbol 686 * @param opts Options for altering program attachment 687 * @return Reference to the newly created BPF link; or NULL is returned on error, 688 * error code is stored in errno 689 */ 690 LIBBPF_API struct bpf_link * 691 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 692 const char *binary_path, size_t func_offset, 693 const struct bpf_uprobe_opts *opts); 694 695 struct bpf_usdt_opts { 696 /* size of this struct, for forward/backward compatibility */ 697 size_t sz; 698 /* custom user-provided value accessible through usdt_cookie() */ 699 __u64 usdt_cookie; 700 size_t :0; 701 }; 702 #define bpf_usdt_opts__last_field usdt_cookie 703 704 /** 705 * @brief **bpf_program__attach_usdt()** is just like 706 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 707 * Statically Defined Tracepoint) attachment, instead of attaching to 708 * user-space function entry or exit. 709 * 710 * @param prog BPF program to attach 711 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 712 * -1 for all processes 713 * @param binary_path Path to binary that contains provided USDT probe 714 * @param usdt_provider USDT provider name 715 * @param usdt_name USDT probe name 716 * @param opts Options for altering program attachment 717 * @return Reference to the newly created BPF link; or NULL is returned on error, 718 * error code is stored in errno 719 */ 720 LIBBPF_API struct bpf_link * 721 bpf_program__attach_usdt(const struct bpf_program *prog, 722 pid_t pid, const char *binary_path, 723 const char *usdt_provider, const char *usdt_name, 724 const struct bpf_usdt_opts *opts); 725 726 struct bpf_tracepoint_opts { 727 /* size of this struct, for forward/backward compatibility */ 728 size_t sz; 729 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 730 __u64 bpf_cookie; 731 }; 732 #define bpf_tracepoint_opts__last_field bpf_cookie 733 734 LIBBPF_API struct bpf_link * 735 bpf_program__attach_tracepoint(const struct bpf_program *prog, 736 const char *tp_category, 737 const char *tp_name); 738 LIBBPF_API struct bpf_link * 739 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 740 const char *tp_category, 741 const char *tp_name, 742 const struct bpf_tracepoint_opts *opts); 743 744 LIBBPF_API struct bpf_link * 745 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 746 const char *tp_name); 747 748 struct bpf_trace_opts { 749 /* size of this struct, for forward/backward compatibility */ 750 size_t sz; 751 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 752 __u64 cookie; 753 }; 754 #define bpf_trace_opts__last_field cookie 755 756 LIBBPF_API struct bpf_link * 757 bpf_program__attach_trace(const struct bpf_program *prog); 758 LIBBPF_API struct bpf_link * 759 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 760 761 LIBBPF_API struct bpf_link * 762 bpf_program__attach_lsm(const struct bpf_program *prog); 763 LIBBPF_API struct bpf_link * 764 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 765 LIBBPF_API struct bpf_link * 766 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 767 LIBBPF_API struct bpf_link * 768 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 769 LIBBPF_API struct bpf_link * 770 bpf_program__attach_freplace(const struct bpf_program *prog, 771 int target_fd, const char *attach_func_name); 772 773 struct bpf_netfilter_opts { 774 /* size of this struct, for forward/backward compatibility */ 775 size_t sz; 776 777 __u32 pf; 778 __u32 hooknum; 779 __s32 priority; 780 __u32 flags; 781 }; 782 #define bpf_netfilter_opts__last_field flags 783 784 LIBBPF_API struct bpf_link * 785 bpf_program__attach_netfilter(const struct bpf_program *prog, 786 const struct bpf_netfilter_opts *opts); 787 788 struct bpf_tcx_opts { 789 /* size of this struct, for forward/backward compatibility */ 790 size_t sz; 791 __u32 flags; 792 __u32 relative_fd; 793 __u32 relative_id; 794 __u64 expected_revision; 795 size_t :0; 796 }; 797 #define bpf_tcx_opts__last_field expected_revision 798 799 LIBBPF_API struct bpf_link * 800 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, 801 const struct bpf_tcx_opts *opts); 802 803 struct bpf_map; 804 805 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 806 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); 807 808 struct bpf_iter_attach_opts { 809 size_t sz; /* size of this struct for forward/backward compatibility */ 810 union bpf_iter_link_info *link_info; 811 __u32 link_info_len; 812 }; 813 #define bpf_iter_attach_opts__last_field link_info_len 814 815 LIBBPF_API struct bpf_link * 816 bpf_program__attach_iter(const struct bpf_program *prog, 817 const struct bpf_iter_attach_opts *opts); 818 819 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 820 821 /** 822 * @brief **bpf_program__set_type()** sets the program 823 * type of the passed BPF program. 824 * @param prog BPF program to set the program type for 825 * @param type program type to set the BPF map to have 826 * @return error code; or 0 if no error. An error occurs 827 * if the object is already loaded. 828 * 829 * This must be called before the BPF object is loaded, 830 * otherwise it has no effect and an error is returned. 831 */ 832 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 833 enum bpf_prog_type type); 834 835 LIBBPF_API enum bpf_attach_type 836 bpf_program__expected_attach_type(const struct bpf_program *prog); 837 838 /** 839 * @brief **bpf_program__set_expected_attach_type()** sets the 840 * attach type of the passed BPF program. This is used for 841 * auto-detection of attachment when programs are loaded. 842 * @param prog BPF program to set the attach type for 843 * @param type attach type to set the BPF map to have 844 * @return error code; or 0 if no error. An error occurs 845 * if the object is already loaded. 846 * 847 * This must be called before the BPF object is loaded, 848 * otherwise it has no effect and an error is returned. 849 */ 850 LIBBPF_API int 851 bpf_program__set_expected_attach_type(struct bpf_program *prog, 852 enum bpf_attach_type type); 853 854 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 855 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 856 857 /* Per-program log level and log buffer getters/setters. 858 * See bpf_object_open_opts comments regarding log_level and log_buf 859 * interactions. 860 */ 861 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 862 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 863 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 864 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 865 866 /** 867 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 868 * for supported BPF program types: 869 * - BTF-aware raw tracepoints (tp_btf); 870 * - fentry/fexit/fmod_ret; 871 * - lsm; 872 * - freplace. 873 * @param prog BPF program to set the attach type for 874 * @param type attach type to set the BPF map to have 875 * @return error code; or 0 if no error occurred. 876 */ 877 LIBBPF_API int 878 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 879 const char *attach_func_name); 880 881 /** 882 * @brief **bpf_object__find_map_by_name()** returns BPF map of 883 * the given name, if it exists within the passed BPF object 884 * @param obj BPF object 885 * @param name name of the BPF map 886 * @return BPF map instance, if such map exists within the BPF object; 887 * or NULL otherwise. 888 */ 889 LIBBPF_API struct bpf_map * 890 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 891 892 LIBBPF_API int 893 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 894 895 LIBBPF_API struct bpf_map * 896 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 897 898 #define bpf_object__for_each_map(pos, obj) \ 899 for ((pos) = bpf_object__next_map((obj), NULL); \ 900 (pos) != NULL; \ 901 (pos) = bpf_object__next_map((obj), (pos))) 902 #define bpf_map__for_each bpf_object__for_each_map 903 904 LIBBPF_API struct bpf_map * 905 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 906 907 /** 908 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 909 * BPF map during BPF object load phase. 910 * @param map the BPF map instance 911 * @param autocreate whether to create BPF map during BPF object load 912 * @return 0 on success; -EBUSY if BPF object was already loaded 913 * 914 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 915 * BPF map. By default, libbpf will attempt to create every single BPF map 916 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 917 * and fill in map FD in BPF instructions. 918 * 919 * This API allows to opt-out of this process for specific map instance. This 920 * can be useful if host kernel doesn't support such BPF map type or used 921 * combination of flags and user application wants to avoid creating such 922 * a map in the first place. User is still responsible to make sure that their 923 * BPF-side code that expects to use such missing BPF map is recognized by BPF 924 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 925 */ 926 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 927 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 928 929 /** 930 * @brief **bpf_map__fd()** gets the file descriptor of the passed 931 * BPF map 932 * @param map the BPF map instance 933 * @return the file descriptor; or -EINVAL in case of an error 934 */ 935 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 936 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 937 /* get map name */ 938 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 939 /* get/set map type */ 940 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 941 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 942 /* get/set map size (max_entries) */ 943 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 944 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 945 /* get/set map flags */ 946 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 947 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 948 /* get/set map NUMA node */ 949 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 950 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 951 /* get/set map key size */ 952 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 953 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 954 /* get map value size */ 955 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 956 /** 957 * @brief **bpf_map__set_value_size()** sets map value size. 958 * @param map the BPF map instance 959 * @return 0, on success; negative error, otherwise 960 * 961 * There is a special case for maps with associated memory-mapped regions, like 962 * the global data section maps (bss, data, rodata). When this function is used 963 * on such a map, the mapped region is resized. Afterward, an attempt is made to 964 * adjust the corresponding BTF info. This attempt is best-effort and can only 965 * succeed if the last variable of the data section map is an array. The array 966 * BTF type is replaced by a new BTF array type with a different length. 967 * Any previously existing pointers returned from bpf_map__initial_value() or 968 * corresponding data section skeleton pointer must be reinitialized. 969 */ 970 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 971 /* get map key/value BTF type IDs */ 972 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 973 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 974 /* get/set map if_index */ 975 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 976 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 977 /* get/set map map_extra flags */ 978 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 979 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 980 981 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 982 const void *data, size_t size); 983 LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize); 984 985 /** 986 * @brief **bpf_map__is_internal()** tells the caller whether or not the 987 * passed map is a special map created by libbpf automatically for things like 988 * global variables, __ksym externs, Kconfig values, etc 989 * @param map the bpf_map 990 * @return true, if the map is an internal map; false, otherwise 991 */ 992 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 993 994 /** 995 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the 996 * BPF map should be pinned. This does not actually create the 'pin'. 997 * @param map The bpf_map 998 * @param path The path 999 * @return 0, on success; negative error, otherwise 1000 */ 1001 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 1002 1003 /** 1004 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the 1005 * BPF map should be pinned. 1006 * @param map The bpf_map 1007 * @return The path string; which can be NULL 1008 */ 1009 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 1010 1011 /** 1012 * @brief **bpf_map__is_pinned()** tells the caller whether or not the 1013 * passed map has been pinned via a 'pin' file. 1014 * @param map The bpf_map 1015 * @return true, if the map is pinned; false, otherwise 1016 */ 1017 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 1018 1019 /** 1020 * @brief **bpf_map__pin()** creates a file that serves as a 'pin' 1021 * for the BPF map. This increments the reference count on the 1022 * BPF map which will keep the BPF map loaded even after the 1023 * userspace process which loaded it has exited. 1024 * @param map The bpf_map to pin 1025 * @param path A file path for the 'pin' 1026 * @return 0, on success; negative error, otherwise 1027 * 1028 * If `path` is NULL the maps `pin_path` attribute will be used. If this is 1029 * also NULL, an error will be returned and the map will not be pinned. 1030 */ 1031 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 1032 1033 /** 1034 * @brief **bpf_map__unpin()** removes the file that serves as a 1035 * 'pin' for the BPF map. 1036 * @param map The bpf_map to unpin 1037 * @param path A file path for the 'pin' 1038 * @return 0, on success; negative error, otherwise 1039 * 1040 * The `path` parameter can be NULL, in which case the `pin_path` 1041 * map attribute is unpinned. If both the `path` parameter and 1042 * `pin_path` map attribute are set, they must be equal. 1043 */ 1044 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 1045 1046 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 1047 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 1048 1049 /** 1050 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 1051 * corresponding to provided key. 1052 * @param map BPF map to lookup element in 1053 * @param key pointer to memory containing bytes of the key used for lookup 1054 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1055 * @param value pointer to memory in which looked up value will be stored 1056 * @param value_sz size in byte of value data memory; it has to match BPF map 1057 * definition's **value_size**. For per-CPU BPF maps value size has to be 1058 * a product of BPF map value size and number of possible CPUs in the system 1059 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1060 * per-CPU values value size has to be aligned up to closest 8 bytes for 1061 * alignment reasons, so expected size is: `round_up(value_size, 8) 1062 * * libbpf_num_possible_cpus()`. 1063 * @flags extra flags passed to kernel for this operation 1064 * @return 0, on success; negative error, otherwise 1065 * 1066 * **bpf_map__lookup_elem()** is high-level equivalent of 1067 * **bpf_map_lookup_elem()** API with added check for key and value size. 1068 */ 1069 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 1070 const void *key, size_t key_sz, 1071 void *value, size_t value_sz, __u64 flags); 1072 1073 /** 1074 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 1075 * map that corresponds to provided key. 1076 * @param map BPF map to insert to or update element in 1077 * @param key pointer to memory containing bytes of the key 1078 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1079 * @param value pointer to memory containing bytes of the value 1080 * @param value_sz size in byte of value data memory; it has to match BPF map 1081 * definition's **value_size**. For per-CPU BPF maps value size has to be 1082 * a product of BPF map value size and number of possible CPUs in the system 1083 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1084 * per-CPU values value size has to be aligned up to closest 8 bytes for 1085 * alignment reasons, so expected size is: `round_up(value_size, 8) 1086 * * libbpf_num_possible_cpus()`. 1087 * @flags extra flags passed to kernel for this operation 1088 * @return 0, on success; negative error, otherwise 1089 * 1090 * **bpf_map__update_elem()** is high-level equivalent of 1091 * **bpf_map_update_elem()** API with added check for key and value size. 1092 */ 1093 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 1094 const void *key, size_t key_sz, 1095 const void *value, size_t value_sz, __u64 flags); 1096 1097 /** 1098 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 1099 * corresponds to provided key. 1100 * @param map BPF map to delete element from 1101 * @param key pointer to memory containing bytes of the key 1102 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1103 * @flags extra flags passed to kernel for this operation 1104 * @return 0, on success; negative error, otherwise 1105 * 1106 * **bpf_map__delete_elem()** is high-level equivalent of 1107 * **bpf_map_delete_elem()** API with added check for key size. 1108 */ 1109 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 1110 const void *key, size_t key_sz, __u64 flags); 1111 1112 /** 1113 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 1114 * corresponding to provided key and atomically delete it afterwards. 1115 * @param map BPF map to lookup element in 1116 * @param key pointer to memory containing bytes of the key used for lookup 1117 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1118 * @param value pointer to memory in which looked up value will be stored 1119 * @param value_sz size in byte of value data memory; it has to match BPF map 1120 * definition's **value_size**. For per-CPU BPF maps value size has to be 1121 * a product of BPF map value size and number of possible CPUs in the system 1122 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 1123 * per-CPU values value size has to be aligned up to closest 8 bytes for 1124 * alignment reasons, so expected size is: `round_up(value_size, 8) 1125 * * libbpf_num_possible_cpus()`. 1126 * @flags extra flags passed to kernel for this operation 1127 * @return 0, on success; negative error, otherwise 1128 * 1129 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 1130 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 1131 */ 1132 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 1133 const void *key, size_t key_sz, 1134 void *value, size_t value_sz, __u64 flags); 1135 1136 /** 1137 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 1138 * fetching next key that follows current key. 1139 * @param map BPF map to fetch next key from 1140 * @param cur_key pointer to memory containing bytes of current key or NULL to 1141 * fetch the first key 1142 * @param next_key pointer to memory to write next key into 1143 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 1144 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 1145 * negative error, otherwise 1146 * 1147 * **bpf_map__get_next_key()** is high-level equivalent of 1148 * **bpf_map_get_next_key()** API with added check for key size. 1149 */ 1150 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 1151 const void *cur_key, void *next_key, size_t key_sz); 1152 1153 struct bpf_xdp_set_link_opts { 1154 size_t sz; 1155 int old_fd; 1156 size_t :0; 1157 }; 1158 #define bpf_xdp_set_link_opts__last_field old_fd 1159 1160 struct bpf_xdp_attach_opts { 1161 size_t sz; 1162 int old_prog_fd; 1163 size_t :0; 1164 }; 1165 #define bpf_xdp_attach_opts__last_field old_prog_fd 1166 1167 struct bpf_xdp_query_opts { 1168 size_t sz; 1169 __u32 prog_id; /* output */ 1170 __u32 drv_prog_id; /* output */ 1171 __u32 hw_prog_id; /* output */ 1172 __u32 skb_prog_id; /* output */ 1173 __u8 attach_mode; /* output */ 1174 __u64 feature_flags; /* output */ 1175 __u32 xdp_zc_max_segs; /* output */ 1176 size_t :0; 1177 }; 1178 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs 1179 1180 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 1181 const struct bpf_xdp_attach_opts *opts); 1182 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 1183 const struct bpf_xdp_attach_opts *opts); 1184 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 1185 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 1186 1187 /* TC related API */ 1188 enum bpf_tc_attach_point { 1189 BPF_TC_INGRESS = 1 << 0, 1190 BPF_TC_EGRESS = 1 << 1, 1191 BPF_TC_CUSTOM = 1 << 2, 1192 }; 1193 1194 #define BPF_TC_PARENT(a, b) \ 1195 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 1196 1197 enum bpf_tc_flags { 1198 BPF_TC_F_REPLACE = 1 << 0, 1199 }; 1200 1201 struct bpf_tc_hook { 1202 size_t sz; 1203 int ifindex; 1204 enum bpf_tc_attach_point attach_point; 1205 __u32 parent; 1206 size_t :0; 1207 }; 1208 #define bpf_tc_hook__last_field parent 1209 1210 struct bpf_tc_opts { 1211 size_t sz; 1212 int prog_fd; 1213 __u32 flags; 1214 __u32 prog_id; 1215 __u32 handle; 1216 __u32 priority; 1217 size_t :0; 1218 }; 1219 #define bpf_tc_opts__last_field priority 1220 1221 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 1222 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 1223 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 1224 struct bpf_tc_opts *opts); 1225 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 1226 const struct bpf_tc_opts *opts); 1227 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 1228 struct bpf_tc_opts *opts); 1229 1230 /* Ring buffer APIs */ 1231 struct ring_buffer; 1232 struct user_ring_buffer; 1233 1234 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 1235 1236 struct ring_buffer_opts { 1237 size_t sz; /* size of this struct, for forward/backward compatibility */ 1238 }; 1239 1240 #define ring_buffer_opts__last_field sz 1241 1242 LIBBPF_API struct ring_buffer * 1243 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 1244 const struct ring_buffer_opts *opts); 1245 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 1246 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 1247 ring_buffer_sample_fn sample_cb, void *ctx); 1248 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 1249 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 1250 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 1251 1252 struct user_ring_buffer_opts { 1253 size_t sz; /* size of this struct, for forward/backward compatibility */ 1254 }; 1255 1256 #define user_ring_buffer_opts__last_field sz 1257 1258 /** 1259 * @brief **user_ring_buffer__new()** creates a new instance of a user ring 1260 * buffer. 1261 * 1262 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map. 1263 * @param opts Options for how the ring buffer should be created. 1264 * @return A user ring buffer on success; NULL and errno being set on a 1265 * failure. 1266 */ 1267 LIBBPF_API struct user_ring_buffer * 1268 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); 1269 1270 /** 1271 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the 1272 * user ring buffer. 1273 * @param rb A pointer to a user ring buffer. 1274 * @param size The size of the sample, in bytes. 1275 * @return A pointer to an 8-byte aligned reserved region of the user ring 1276 * buffer; NULL, and errno being set if a sample could not be reserved. 1277 * 1278 * This function is *not* thread safe, and callers must synchronize accessing 1279 * this function if there are multiple producers. If a size is requested that 1280 * is larger than the size of the entire ring buffer, errno will be set to 1281 * E2BIG and NULL is returned. If the ring buffer could accommodate the size, 1282 * but currently does not have enough space, errno is set to ENOSPC and NULL is 1283 * returned. 1284 * 1285 * After initializing the sample, callers must invoke 1286 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise, 1287 * the sample must be freed with **user_ring_buffer__discard()**. 1288 */ 1289 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); 1290 1291 /** 1292 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the 1293 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes 1294 * available. 1295 * @param rb The user ring buffer. 1296 * @param size The size of the sample, in bytes. 1297 * @param timeout_ms The amount of time, in milliseconds, for which the caller 1298 * should block when waiting for a sample. -1 causes the caller to block 1299 * indefinitely. 1300 * @return A pointer to an 8-byte aligned reserved region of the user ring 1301 * buffer; NULL, and errno being set if a sample could not be reserved. 1302 * 1303 * This function is *not* thread safe, and callers must synchronize 1304 * accessing this function if there are multiple producers 1305 * 1306 * If **timeout_ms** is -1, the function will block indefinitely until a sample 1307 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno 1308 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking 1309 * will occur and the function will return immediately after attempting to 1310 * reserve a sample. 1311 * 1312 * If **size** is larger than the size of the entire ring buffer, errno is set 1313 * to E2BIG and NULL is returned. If the ring buffer could accommodate 1314 * **size**, but currently does not have enough space, the caller will block 1315 * until at most **timeout_ms** has elapsed. If insufficient space is available 1316 * at that time, errno is set to ENOSPC, and NULL is returned. 1317 * 1318 * The kernel guarantees that it will wake up this thread to check if 1319 * sufficient space is available in the ring buffer at least once per 1320 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at 1321 * least one sample is consumed, and the BPF program did not invoke the 1322 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the 1323 * kernel does not guarantee this. If the helper function is invoked with 1324 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is 1325 * consumed. 1326 * 1327 * When a sample of size **size** is found within **timeout_ms**, a pointer to 1328 * the sample is returned. After initializing the sample, callers must invoke 1329 * **user_ring_buffer__submit()** to post the sample to the ring buffer. 1330 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**. 1331 */ 1332 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, 1333 __u32 size, 1334 int timeout_ms); 1335 1336 /** 1337 * @brief **user_ring_buffer__submit()** submits a previously reserved sample 1338 * into the ring buffer. 1339 * @param rb The user ring buffer. 1340 * @param sample A reserved sample. 1341 * 1342 * It is not necessary to synchronize amongst multiple producers when invoking 1343 * this function. 1344 */ 1345 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); 1346 1347 /** 1348 * @brief **user_ring_buffer__discard()** discards a previously reserved sample. 1349 * @param rb The user ring buffer. 1350 * @param sample A reserved sample. 1351 * 1352 * It is not necessary to synchronize amongst multiple producers when invoking 1353 * this function. 1354 */ 1355 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample); 1356 1357 /** 1358 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously 1359 * created with **user_ring_buffer__new()**. 1360 * @param rb The user ring buffer being freed. 1361 */ 1362 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb); 1363 1364 /* Perf buffer APIs */ 1365 struct perf_buffer; 1366 1367 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 1368 void *data, __u32 size); 1369 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 1370 1371 /* common use perf buffer options */ 1372 struct perf_buffer_opts { 1373 size_t sz; 1374 __u32 sample_period; 1375 size_t :0; 1376 }; 1377 #define perf_buffer_opts__last_field sample_period 1378 1379 /** 1380 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1381 * BPF_PERF_EVENT_ARRAY map 1382 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1383 * code to send data over to user-space 1384 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1385 * @param sample_cb function called on each received data record 1386 * @param lost_cb function called when record loss has occurred 1387 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1388 * @return a new instance of struct perf_buffer on success, NULL on error with 1389 * *errno* containing an error code 1390 */ 1391 LIBBPF_API struct perf_buffer * 1392 perf_buffer__new(int map_fd, size_t page_cnt, 1393 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1394 const struct perf_buffer_opts *opts); 1395 1396 enum bpf_perf_event_ret { 1397 LIBBPF_PERF_EVENT_DONE = 0, 1398 LIBBPF_PERF_EVENT_ERROR = -1, 1399 LIBBPF_PERF_EVENT_CONT = -2, 1400 }; 1401 1402 struct perf_event_header; 1403 1404 typedef enum bpf_perf_event_ret 1405 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1406 1407 /* raw perf buffer options, giving most power and control */ 1408 struct perf_buffer_raw_opts { 1409 size_t sz; 1410 long :0; 1411 long :0; 1412 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1413 * max_entries of given PERF_EVENT_ARRAY map) 1414 */ 1415 int cpu_cnt; 1416 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1417 int *cpus; 1418 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1419 int *map_keys; 1420 }; 1421 #define perf_buffer_raw_opts__last_field map_keys 1422 1423 struct perf_event_attr; 1424 1425 LIBBPF_API struct perf_buffer * 1426 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1427 perf_buffer_event_fn event_cb, void *ctx, 1428 const struct perf_buffer_raw_opts *opts); 1429 1430 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1431 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1432 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1433 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1434 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1435 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1436 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1437 /** 1438 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying 1439 * memory region of the ring buffer. 1440 * This ring buffer can be used to implement a custom events consumer. 1441 * The ring buffer starts with the *struct perf_event_mmap_page*, which 1442 * holds the ring buffer managment fields, when accessing the header 1443 * structure it's important to be SMP aware. 1444 * You can refer to *perf_event_read_simple* for a simple example. 1445 * @param pb the perf buffer structure 1446 * @param buf_idx the buffer index to retreive 1447 * @param buf (out) gets the base pointer of the mmap()'ed memory 1448 * @param buf_size (out) gets the size of the mmap()'ed region 1449 * @return 0 on success, negative error code for failure 1450 */ 1451 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, 1452 size_t *buf_size); 1453 1454 struct bpf_prog_linfo; 1455 struct bpf_prog_info; 1456 1457 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1458 LIBBPF_API struct bpf_prog_linfo * 1459 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1460 LIBBPF_API const struct bpf_line_info * 1461 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1462 __u64 addr, __u32 func_idx, __u32 nr_skip); 1463 LIBBPF_API const struct bpf_line_info * 1464 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1465 __u32 insn_off, __u32 nr_skip); 1466 1467 /* 1468 * Probe for supported system features 1469 * 1470 * Note that running many of these probes in a short amount of time can cause 1471 * the kernel to reach the maximal size of lockable memory allowed for the 1472 * user, causing subsequent probes to fail. In this case, the caller may want 1473 * to adjust that limit with setrlimit(). 1474 */ 1475 1476 /** 1477 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1478 * BPF programs of a given type. 1479 * @param prog_type BPF program type to detect kernel support for 1480 * @param opts reserved for future extensibility, should be NULL 1481 * @return 1, if given program type is supported; 0, if given program type is 1482 * not supported; negative error code if feature detection failed or can't be 1483 * performed 1484 * 1485 * Make sure the process has required set of CAP_* permissions (or runs as 1486 * root) when performing feature checking. 1487 */ 1488 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1489 /** 1490 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1491 * BPF maps of a given type. 1492 * @param map_type BPF map type to detect kernel support for 1493 * @param opts reserved for future extensibility, should be NULL 1494 * @return 1, if given map type is supported; 0, if given map type is 1495 * not supported; negative error code if feature detection failed or can't be 1496 * performed 1497 * 1498 * Make sure the process has required set of CAP_* permissions (or runs as 1499 * root) when performing feature checking. 1500 */ 1501 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1502 /** 1503 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1504 * use of a given BPF helper from specified BPF program type. 1505 * @param prog_type BPF program type used to check the support of BPF helper 1506 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1507 * @param opts reserved for future extensibility, should be NULL 1508 * @return 1, if given combination of program type and helper is supported; 0, 1509 * if the combination is not supported; negative error code if feature 1510 * detection for provided input arguments failed or can't be performed 1511 * 1512 * Make sure the process has required set of CAP_* permissions (or runs as 1513 * root) when performing feature checking. 1514 */ 1515 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1516 enum bpf_func_id helper_id, const void *opts); 1517 1518 /** 1519 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1520 * number of possible CPUs that the host kernel supports and expects. 1521 * @return number of possible CPUs; or error code on failure 1522 * 1523 * Example usage: 1524 * 1525 * int ncpus = libbpf_num_possible_cpus(); 1526 * if (ncpus < 0) { 1527 * // error handling 1528 * } 1529 * long values[ncpus]; 1530 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1531 */ 1532 LIBBPF_API int libbpf_num_possible_cpus(void); 1533 1534 struct bpf_map_skeleton { 1535 const char *name; 1536 struct bpf_map **map; 1537 void **mmaped; 1538 }; 1539 1540 struct bpf_prog_skeleton { 1541 const char *name; 1542 struct bpf_program **prog; 1543 struct bpf_link **link; 1544 }; 1545 1546 struct bpf_object_skeleton { 1547 size_t sz; /* size of this struct, for forward/backward compatibility */ 1548 1549 const char *name; 1550 const void *data; 1551 size_t data_sz; 1552 1553 struct bpf_object **obj; 1554 1555 int map_cnt; 1556 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1557 struct bpf_map_skeleton *maps; 1558 1559 int prog_cnt; 1560 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1561 struct bpf_prog_skeleton *progs; 1562 }; 1563 1564 LIBBPF_API int 1565 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1566 const struct bpf_object_open_opts *opts); 1567 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1568 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1569 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1570 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1571 1572 struct bpf_var_skeleton { 1573 const char *name; 1574 struct bpf_map **map; 1575 void **addr; 1576 }; 1577 1578 struct bpf_object_subskeleton { 1579 size_t sz; /* size of this struct, for forward/backward compatibility */ 1580 1581 const struct bpf_object *obj; 1582 1583 int map_cnt; 1584 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1585 struct bpf_map_skeleton *maps; 1586 1587 int prog_cnt; 1588 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1589 struct bpf_prog_skeleton *progs; 1590 1591 int var_cnt; 1592 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1593 struct bpf_var_skeleton *vars; 1594 }; 1595 1596 LIBBPF_API int 1597 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1598 LIBBPF_API void 1599 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1600 1601 struct gen_loader_opts { 1602 size_t sz; /* size of this struct, for forward/backward compatibility */ 1603 const char *data; 1604 const char *insns; 1605 __u32 data_sz; 1606 __u32 insns_sz; 1607 }; 1608 1609 #define gen_loader_opts__last_field insns_sz 1610 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1611 struct gen_loader_opts *opts); 1612 1613 enum libbpf_tristate { 1614 TRI_NO = 0, 1615 TRI_YES = 1, 1616 TRI_MODULE = 2, 1617 }; 1618 1619 struct bpf_linker_opts { 1620 /* size of this struct, for forward/backward compatibility */ 1621 size_t sz; 1622 }; 1623 #define bpf_linker_opts__last_field sz 1624 1625 struct bpf_linker_file_opts { 1626 /* size of this struct, for forward/backward compatibility */ 1627 size_t sz; 1628 }; 1629 #define bpf_linker_file_opts__last_field sz 1630 1631 struct bpf_linker; 1632 1633 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1634 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1635 const char *filename, 1636 const struct bpf_linker_file_opts *opts); 1637 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1638 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1639 1640 /* 1641 * Custom handling of BPF program's SEC() definitions 1642 */ 1643 1644 struct bpf_prog_load_opts; /* defined in bpf.h */ 1645 1646 /* Called during bpf_object__open() for each recognized BPF program. Callback 1647 * can use various bpf_program__set_*() setters to adjust whatever properties 1648 * are necessary. 1649 */ 1650 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1651 1652 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1653 * into the kernel. Callback can adjust opts as necessary. 1654 */ 1655 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1656 struct bpf_prog_load_opts *opts, long cookie); 1657 1658 /* Called during skeleton attach or through bpf_program__attach(). If 1659 * auto-attach is not supported, callback should return 0 and set link to 1660 * NULL (it's not considered an error during skeleton attach, but it will be 1661 * an error for bpf_program__attach() calls). On error, error should be 1662 * returned directly and link set to NULL. On success, return 0 and set link 1663 * to a valid struct bpf_link. 1664 */ 1665 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1666 struct bpf_link **link); 1667 1668 struct libbpf_prog_handler_opts { 1669 /* size of this struct, for forward/backward compatibility */ 1670 size_t sz; 1671 /* User-provided value that is passed to prog_setup_fn, 1672 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1673 * register one set of callbacks for multiple SEC() definitions and 1674 * still be able to distinguish them, if necessary. For example, 1675 * libbpf itself is using this to pass necessary flags (e.g., 1676 * sleepable flag) to a common internal SEC() handler. 1677 */ 1678 long cookie; 1679 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1680 * Callback is optional, pass NULL if it's not necessary. 1681 */ 1682 libbpf_prog_setup_fn_t prog_setup_fn; 1683 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1684 * Callback is optional, pass NULL if it's not necessary. 1685 */ 1686 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1687 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1688 * Callback is optional, pass NULL if it's not necessary. 1689 */ 1690 libbpf_prog_attach_fn_t prog_attach_fn; 1691 }; 1692 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1693 1694 /** 1695 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1696 * SEC() handler. 1697 * @param sec section prefix for which custom handler is registered 1698 * @param prog_type BPF program type associated with specified section 1699 * @param exp_attach_type Expected BPF attach type associated with specified section 1700 * @param opts optional cookie, callbacks, and other extra options 1701 * @return Non-negative handler ID is returned on success. This handler ID has 1702 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1703 * custom handler. Negative error code is returned on error. 1704 * 1705 * *sec* defines which SEC() definitions are handled by this custom handler 1706 * registration. *sec* can have few different forms: 1707 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1708 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1709 * in an error; 1710 * - if *sec* is of the form "abc/", proper SEC() form is 1711 * SEC("abc/something"), where acceptable "something" should be checked by 1712 * *prog_init_fn* callback, if there are additional restrictions; 1713 * - if *sec* is of the form "abc+", it will successfully match both 1714 * SEC("abc") and SEC("abc/whatever") forms; 1715 * - if *sec* is NULL, custom handler is registered for any BPF program that 1716 * doesn't match any of the registered (custom or libbpf's own) SEC() 1717 * handlers. There could be only one such generic custom handler registered 1718 * at any given time. 1719 * 1720 * All custom handlers (except the one with *sec* == NULL) are processed 1721 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1722 * SEC() handlers by registering custom ones for the same section prefix 1723 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1724 * handler). 1725 * 1726 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1727 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1728 * to ensure synchronization if there is a risk of running this API from 1729 * multiple threads simultaneously. 1730 */ 1731 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 1732 enum bpf_prog_type prog_type, 1733 enum bpf_attach_type exp_attach_type, 1734 const struct libbpf_prog_handler_opts *opts); 1735 /** 1736 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 1737 * custom BPF program SEC() handler. 1738 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 1739 * after successful registration 1740 * @return 0 on success, negative error code if handler isn't found 1741 * 1742 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1743 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1744 * to ensure synchronization if there is a risk of running this API from 1745 * multiple threads simultaneously. 1746 */ 1747 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 1748 1749 #ifdef __cplusplus 1750 } /* extern "C" */ 1751 #endif 1752 1753 #endif /* __LIBBPF_LIBBPF_H */ 1754