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 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); 100 101 /* Hide internal to user */ 102 struct bpf_object; 103 104 struct bpf_object_open_opts { 105 /* size of this struct, for forward/backward compatibility */ 106 size_t sz; 107 /* object name override, if provided: 108 * - for object open from file, this will override setting object 109 * name from file path's base name; 110 * - for object open from memory buffer, this will specify an object 111 * name and will override default "<addr>-<buf-size>" name; 112 */ 113 const char *object_name; 114 /* parse map definitions non-strictly, allowing extra attributes/data */ 115 bool relaxed_maps; 116 /* maps that set the 'pinning' attribute in their definition will have 117 * their pin_path attribute set to a file in this directory, and be 118 * auto-pinned to that path on load; defaults to "/sys/fs/bpf". 119 */ 120 const char *pin_root_path; 121 long :0; 122 /* Additional kernel config content that augments and overrides 123 * system Kconfig for CONFIG_xxx externs. 124 */ 125 const char *kconfig; 126 /* Path to the custom BTF to be used for BPF CO-RE relocations. 127 * This custom BTF completely replaces the use of vmlinux BTF 128 * for the purpose of CO-RE relocations. 129 * NOTE: any other BPF feature (e.g., fentry/fexit programs, 130 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. 131 */ 132 const char *btf_custom_path; 133 /* Pointer to a buffer for storing kernel logs for applicable BPF 134 * commands. Valid kernel_log_size has to be specified as well and are 135 * passed-through to bpf() syscall. Keep in mind that kernel might 136 * fail operation with -ENOSPC error if provided buffer is too small 137 * to contain entire log output. 138 * See the comment below for kernel_log_level for interaction between 139 * log_buf and log_level settings. 140 * 141 * If specified, this log buffer will be passed for: 142 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden 143 * with bpf_program__set_log() on per-program level, to get 144 * BPF verifier log output. 145 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get 146 * BTF sanity checking log. 147 * 148 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite 149 * previous contents, so if you need more fine-grained control, set 150 * per-program buffer with bpf_program__set_log_buf() to preserve each 151 * individual program's verification log. Keep using kernel_log_buf 152 * for BTF verification log, if necessary. 153 */ 154 char *kernel_log_buf; 155 size_t kernel_log_size; 156 /* 157 * Log level can be set independently from log buffer. Log_level=0 158 * means that libbpf will attempt loading BTF or program without any 159 * logging requested, but will retry with either its own or custom log 160 * buffer, if provided, and log_level=1 on any error. 161 * And vice versa, setting log_level>0 will request BTF or prog 162 * loading with verbose log from the first attempt (and as such also 163 * for successfully loaded BTF or program), and the actual log buffer 164 * could be either libbpf's own auto-allocated log buffer, if 165 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. 166 * If user didn't provide custom log buffer, libbpf will emit captured 167 * logs through its print callback. 168 */ 169 __u32 kernel_log_level; 170 171 size_t :0; 172 }; 173 #define bpf_object_open_opts__last_field kernel_log_level 174 175 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 176 177 /** 178 * @brief **bpf_object__open_file()** creates a bpf_object by opening 179 * the BPF ELF object file pointed to by the passed path and loading it 180 * into memory. 181 * @param path BPF object file path 182 * @param opts options for how to load the bpf object, this parameter is 183 * optional and can be set to NULL 184 * @return pointer to the new bpf_object; or NULL is returned on error, 185 * error code is stored in errno 186 */ 187 LIBBPF_API struct bpf_object * 188 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); 189 190 /** 191 * @brief **bpf_object__open_mem()** creates a bpf_object by reading 192 * the BPF objects raw bytes from a memory buffer containing a valid 193 * BPF ELF object file. 194 * @param obj_buf pointer to the buffer containing ELF file bytes 195 * @param obj_buf_sz number of bytes in the buffer 196 * @param opts options for how to load the bpf object 197 * @return pointer to the new bpf_object; or NULL is returned on error, 198 * error code is stored in errno 199 */ 200 LIBBPF_API struct bpf_object * 201 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, 202 const struct bpf_object_open_opts *opts); 203 204 /* Load/unload object into/from kernel */ 205 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 206 207 LIBBPF_API void bpf_object__close(struct bpf_object *object); 208 209 /* pin_maps and unpin_maps can both be called with a NULL path, in which case 210 * they will use the pin_path attribute of each map (and ignore all maps that 211 * don't have a pin_path set). 212 */ 213 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 214 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 215 const char *path); 216 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 217 const char *path); 218 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 219 const char *path); 220 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 221 222 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); 223 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); 224 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); 225 226 struct btf; 227 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); 228 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 229 230 LIBBPF_API struct bpf_program * 231 bpf_object__find_program_by_name(const struct bpf_object *obj, 232 const char *name); 233 234 LIBBPF_API int 235 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 236 enum bpf_attach_type *expected_attach_type); 237 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 238 enum bpf_attach_type *attach_type); 239 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, 240 enum bpf_attach_type attach_type); 241 242 /* Accessors of bpf_program */ 243 struct bpf_program; 244 245 LIBBPF_API struct bpf_program * 246 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); 247 248 #define bpf_object__for_each_program(pos, obj) \ 249 for ((pos) = bpf_object__next_program((obj), NULL); \ 250 (pos) != NULL; \ 251 (pos) = bpf_object__next_program((obj), (pos))) 252 253 LIBBPF_API struct bpf_program * 254 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); 255 256 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 257 __u32 ifindex); 258 259 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); 260 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); 261 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); 262 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); 263 264 struct bpf_insn; 265 266 /** 267 * @brief **bpf_program__insns()** gives read-only access to BPF program's 268 * underlying BPF instructions. 269 * @param prog BPF program for which to return instructions 270 * @return a pointer to an array of BPF instructions that belong to the 271 * specified BPF program 272 * 273 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` 274 * pointed to can be fetched using **bpf_program__insn_cnt()** API. 275 * 276 * Keep in mind, libbpf can modify and append/delete BPF program's 277 * instructions as it processes BPF object file and prepares everything for 278 * uploading into the kernel. So depending on the point in BPF object 279 * lifetime, **bpf_program__insns()** can return different sets of 280 * instructions. As an example, during BPF object load phase BPF program 281 * instructions will be CO-RE-relocated, BPF subprograms instructions will be 282 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions 283 * returned before **bpf_object__load()** and after it might be quite 284 * different. 285 */ 286 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); 287 288 /** 289 * @brief **bpf_program__set_insns()** can set BPF program's underlying 290 * BPF instructions. 291 * 292 * WARNING: This is a very advanced libbpf API and users need to know 293 * what they are doing. This should be used from prog_prepare_load_fn 294 * callback only. 295 * 296 * @param prog BPF program for which to return instructions 297 * @param new_insns a pointer to an array of BPF instructions 298 * @param new_insn_cnt number of `struct bpf_insn`'s that form 299 * specified BPF program 300 * @return 0, on success; negative error code, otherwise 301 */ 302 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, 303 struct bpf_insn *new_insns, size_t new_insn_cnt); 304 305 /** 306 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s 307 * that form specified BPF program. 308 * @param prog BPF program for which to return number of BPF instructions 309 * 310 * See **bpf_program__insns()** documentation for notes on how libbpf can 311 * change instructions and their count during different phases of 312 * **bpf_object** lifetime. 313 */ 314 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); 315 316 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); 317 318 /** 319 * @brief **bpf_program__pin()** pins the BPF program to a file 320 * in the BPF FS specified by a path. This increments the programs 321 * reference count, allowing it to stay loaded after the process 322 * which loaded it has exited. 323 * 324 * @param prog BPF program to pin, must already be loaded 325 * @param path file path in a BPF file system 326 * @return 0, on success; negative error code, otherwise 327 */ 328 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 329 330 /** 331 * @brief **bpf_program__unpin()** unpins the BPF program from a file 332 * in the BPFFS specified by a path. This decrements the programs 333 * reference count. 334 * 335 * The file pinning the BPF program can also be unlinked by a different 336 * process in which case this function will return an error. 337 * 338 * @param prog BPF program to unpin 339 * @param path file path to the pin in a BPF file system 340 * @return 0, on success; negative error code, otherwise 341 */ 342 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 343 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 344 345 struct bpf_link; 346 347 LIBBPF_API struct bpf_link *bpf_link__open(const char *path); 348 LIBBPF_API int bpf_link__fd(const struct bpf_link *link); 349 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); 350 /** 351 * @brief **bpf_link__pin()** pins the BPF link to a file 352 * in the BPF FS specified by a path. This increments the links 353 * reference count, allowing it to stay loaded after the process 354 * which loaded it has exited. 355 * 356 * @param link BPF link to pin, must already be loaded 357 * @param path file path in a BPF file system 358 * @return 0, on success; negative error code, otherwise 359 */ 360 361 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); 362 363 /** 364 * @brief **bpf_link__unpin()** unpins the BPF link from a file 365 * in the BPFFS specified by a path. This decrements the links 366 * reference count. 367 * 368 * The file pinning the BPF link can also be unlinked by a different 369 * process in which case this function will return an error. 370 * 371 * @param prog BPF program to unpin 372 * @param path file path to the pin in a BPF file system 373 * @return 0, on success; negative error code, otherwise 374 */ 375 LIBBPF_API int bpf_link__unpin(struct bpf_link *link); 376 LIBBPF_API int bpf_link__update_program(struct bpf_link *link, 377 struct bpf_program *prog); 378 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); 379 LIBBPF_API int bpf_link__detach(struct bpf_link *link); 380 LIBBPF_API int bpf_link__destroy(struct bpf_link *link); 381 382 /** 383 * @brief **bpf_program__attach()** is a generic function for attaching 384 * a BPF program based on auto-detection of program type, attach type, 385 * and extra paremeters, where applicable. 386 * 387 * @param prog BPF program to attach 388 * @return Reference to the newly created BPF link; or NULL is returned on error, 389 * error code is stored in errno 390 * 391 * This is supported for: 392 * - kprobe/kretprobe (depends on SEC() definition) 393 * - uprobe/uretprobe (depends on SEC() definition) 394 * - tracepoint 395 * - raw tracepoint 396 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) 397 */ 398 LIBBPF_API struct bpf_link * 399 bpf_program__attach(const struct bpf_program *prog); 400 401 struct bpf_perf_event_opts { 402 /* size of this struct, for forward/backward compatiblity */ 403 size_t sz; 404 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 405 __u64 bpf_cookie; 406 }; 407 #define bpf_perf_event_opts__last_field bpf_cookie 408 409 LIBBPF_API struct bpf_link * 410 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); 411 412 LIBBPF_API struct bpf_link * 413 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, 414 const struct bpf_perf_event_opts *opts); 415 416 struct bpf_kprobe_opts { 417 /* size of this struct, for forward/backward compatiblity */ 418 size_t sz; 419 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 420 __u64 bpf_cookie; 421 /* function's offset to install kprobe to */ 422 size_t offset; 423 /* kprobe is return probe */ 424 bool retprobe; 425 size_t :0; 426 }; 427 #define bpf_kprobe_opts__last_field retprobe 428 429 LIBBPF_API struct bpf_link * 430 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, 431 const char *func_name); 432 LIBBPF_API struct bpf_link * 433 bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 434 const char *func_name, 435 const struct bpf_kprobe_opts *opts); 436 437 struct bpf_kprobe_multi_opts { 438 /* size of this struct, for forward/backward compatibility */ 439 size_t sz; 440 /* array of function symbols to attach */ 441 const char **syms; 442 /* array of function addresses to attach */ 443 const unsigned long *addrs; 444 /* array of user-provided values fetchable through bpf_get_attach_cookie */ 445 const __u64 *cookies; 446 /* number of elements in syms/addrs/cookies arrays */ 447 size_t cnt; 448 /* create return kprobes */ 449 bool retprobe; 450 size_t :0; 451 }; 452 453 #define bpf_kprobe_multi_opts__last_field retprobe 454 455 LIBBPF_API struct bpf_link * 456 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 457 const char *pattern, 458 const struct bpf_kprobe_multi_opts *opts); 459 460 struct bpf_uprobe_opts { 461 /* size of this struct, for forward/backward compatiblity */ 462 size_t sz; 463 /* offset of kernel reference counted USDT semaphore, added in 464 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 465 */ 466 size_t ref_ctr_offset; 467 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 468 __u64 bpf_cookie; 469 /* uprobe is return probe, invoked at function return time */ 470 bool retprobe; 471 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 472 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 473 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 474 * offset within a function, specify func_name and use func_offset argument to specify 475 * offset within the function. Shared library functions must specify the shared library 476 * binary_path. 477 */ 478 const char *func_name; 479 size_t :0; 480 }; 481 #define bpf_uprobe_opts__last_field func_name 482 483 /** 484 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 485 * to the userspace function which is found by binary path and 486 * offset. You can optionally specify a particular proccess to attach 487 * to. You can also optionally attach the program to the function 488 * exit instead of entry. 489 * 490 * @param prog BPF program to attach 491 * @param retprobe Attach to function exit 492 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 493 * -1 for all processes 494 * @param binary_path Path to binary that contains the function symbol 495 * @param func_offset Offset within the binary of the function symbol 496 * @return Reference to the newly created BPF link; or NULL is returned on error, 497 * error code is stored in errno 498 */ 499 LIBBPF_API struct bpf_link * 500 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 501 pid_t pid, const char *binary_path, 502 size_t func_offset); 503 504 /** 505 * @brief **bpf_program__attach_uprobe_opts()** is just like 506 * bpf_program__attach_uprobe() except with a options struct 507 * for various configurations. 508 * 509 * @param prog BPF program to attach 510 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 511 * -1 for all processes 512 * @param binary_path Path to binary that contains the function symbol 513 * @param func_offset Offset within the binary of the function symbol 514 * @param opts Options for altering program attachment 515 * @return Reference to the newly created BPF link; or NULL is returned on error, 516 * error code is stored in errno 517 */ 518 LIBBPF_API struct bpf_link * 519 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 520 const char *binary_path, size_t func_offset, 521 const struct bpf_uprobe_opts *opts); 522 523 struct bpf_usdt_opts { 524 /* size of this struct, for forward/backward compatibility */ 525 size_t sz; 526 /* custom user-provided value accessible through usdt_cookie() */ 527 __u64 usdt_cookie; 528 size_t :0; 529 }; 530 #define bpf_usdt_opts__last_field usdt_cookie 531 532 /** 533 * @brief **bpf_program__attach_usdt()** is just like 534 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 535 * Statically Defined Tracepoint) attachment, instead of attaching to 536 * user-space function entry or exit. 537 * 538 * @param prog BPF program to attach 539 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 540 * -1 for all processes 541 * @param binary_path Path to binary that contains provided USDT probe 542 * @param usdt_provider USDT provider name 543 * @param usdt_name USDT probe name 544 * @param opts Options for altering program attachment 545 * @return Reference to the newly created BPF link; or NULL is returned on error, 546 * error code is stored in errno 547 */ 548 LIBBPF_API struct bpf_link * 549 bpf_program__attach_usdt(const struct bpf_program *prog, 550 pid_t pid, const char *binary_path, 551 const char *usdt_provider, const char *usdt_name, 552 const struct bpf_usdt_opts *opts); 553 554 struct bpf_tracepoint_opts { 555 /* size of this struct, for forward/backward compatiblity */ 556 size_t sz; 557 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 558 __u64 bpf_cookie; 559 }; 560 #define bpf_tracepoint_opts__last_field bpf_cookie 561 562 LIBBPF_API struct bpf_link * 563 bpf_program__attach_tracepoint(const struct bpf_program *prog, 564 const char *tp_category, 565 const char *tp_name); 566 LIBBPF_API struct bpf_link * 567 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 568 const char *tp_category, 569 const char *tp_name, 570 const struct bpf_tracepoint_opts *opts); 571 572 LIBBPF_API struct bpf_link * 573 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 574 const char *tp_name); 575 576 struct bpf_trace_opts { 577 /* size of this struct, for forward/backward compatibility */ 578 size_t sz; 579 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 580 __u64 cookie; 581 }; 582 #define bpf_trace_opts__last_field cookie 583 584 LIBBPF_API struct bpf_link * 585 bpf_program__attach_trace(const struct bpf_program *prog); 586 LIBBPF_API struct bpf_link * 587 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 588 589 LIBBPF_API struct bpf_link * 590 bpf_program__attach_lsm(const struct bpf_program *prog); 591 LIBBPF_API struct bpf_link * 592 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 593 LIBBPF_API struct bpf_link * 594 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 595 LIBBPF_API struct bpf_link * 596 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 597 LIBBPF_API struct bpf_link * 598 bpf_program__attach_freplace(const struct bpf_program *prog, 599 int target_fd, const char *attach_func_name); 600 601 struct bpf_map; 602 603 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 604 605 struct bpf_iter_attach_opts { 606 size_t sz; /* size of this struct for forward/backward compatibility */ 607 union bpf_iter_link_info *link_info; 608 __u32 link_info_len; 609 }; 610 #define bpf_iter_attach_opts__last_field link_info_len 611 612 LIBBPF_API struct bpf_link * 613 bpf_program__attach_iter(const struct bpf_program *prog, 614 const struct bpf_iter_attach_opts *opts); 615 616 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 617 618 /** 619 * @brief **bpf_program__set_type()** sets the program 620 * type of the passed BPF program. 621 * @param prog BPF program to set the program type for 622 * @param type program type to set the BPF map to have 623 * @return error code; or 0 if no error. An error occurs 624 * if the object is already loaded. 625 * 626 * This must be called before the BPF object is loaded, 627 * otherwise it has no effect and an error is returned. 628 */ 629 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 630 enum bpf_prog_type type); 631 632 LIBBPF_API enum bpf_attach_type 633 bpf_program__expected_attach_type(const struct bpf_program *prog); 634 635 /** 636 * @brief **bpf_program__set_expected_attach_type()** sets the 637 * attach type of the passed BPF program. This is used for 638 * auto-detection of attachment when programs are loaded. 639 * @param prog BPF program to set the attach type for 640 * @param type attach type to set the BPF map to have 641 * @return error code; or 0 if no error. An error occurs 642 * if the object is already loaded. 643 * 644 * This must be called before the BPF object is loaded, 645 * otherwise it has no effect and an error is returned. 646 */ 647 LIBBPF_API int 648 bpf_program__set_expected_attach_type(struct bpf_program *prog, 649 enum bpf_attach_type type); 650 651 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 652 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 653 654 /* Per-program log level and log buffer getters/setters. 655 * See bpf_object_open_opts comments regarding log_level and log_buf 656 * interactions. 657 */ 658 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 659 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 660 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 661 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 662 663 /** 664 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 665 * for supported BPF program types: 666 * - BTF-aware raw tracepoints (tp_btf); 667 * - fentry/fexit/fmod_ret; 668 * - lsm; 669 * - freplace. 670 * @param prog BPF program to set the attach type for 671 * @param type attach type to set the BPF map to have 672 * @return error code; or 0 if no error occurred. 673 */ 674 LIBBPF_API int 675 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 676 const char *attach_func_name); 677 678 /** 679 * @brief **bpf_object__find_map_by_name()** returns BPF map of 680 * the given name, if it exists within the passed BPF object 681 * @param obj BPF object 682 * @param name name of the BPF map 683 * @return BPF map instance, if such map exists within the BPF object; 684 * or NULL otherwise. 685 */ 686 LIBBPF_API struct bpf_map * 687 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 688 689 LIBBPF_API int 690 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 691 692 LIBBPF_API struct bpf_map * 693 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 694 695 #define bpf_object__for_each_map(pos, obj) \ 696 for ((pos) = bpf_object__next_map((obj), NULL); \ 697 (pos) != NULL; \ 698 (pos) = bpf_object__next_map((obj), (pos))) 699 #define bpf_map__for_each bpf_object__for_each_map 700 701 LIBBPF_API struct bpf_map * 702 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 703 704 /** 705 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 706 * BPF map during BPF object load phase. 707 * @param map the BPF map instance 708 * @param autocreate whether to create BPF map during BPF object load 709 * @return 0 on success; -EBUSY if BPF object was already loaded 710 * 711 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 712 * BPF map. By default, libbpf will attempt to create every single BPF map 713 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 714 * and fill in map FD in BPF instructions. 715 * 716 * This API allows to opt-out of this process for specific map instance. This 717 * can be useful if host kernel doesn't support such BPF map type or used 718 * combination of flags and user application wants to avoid creating such 719 * a map in the first place. User is still responsible to make sure that their 720 * BPF-side code that expects to use such missing BPF map is recognized by BPF 721 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 722 */ 723 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 724 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 725 726 /** 727 * @brief **bpf_map__fd()** gets the file descriptor of the passed 728 * BPF map 729 * @param map the BPF map instance 730 * @return the file descriptor; or -EINVAL in case of an error 731 */ 732 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 733 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 734 /* get map name */ 735 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 736 /* get/set map type */ 737 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 738 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 739 /* get/set map size (max_entries) */ 740 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 741 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 742 /* get/set map flags */ 743 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 744 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 745 /* get/set map NUMA node */ 746 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 747 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 748 /* get/set map key size */ 749 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 750 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 751 /* get/set map value size */ 752 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 753 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 754 /* get map key/value BTF type IDs */ 755 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 756 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 757 /* get/set map if_index */ 758 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 759 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 760 /* get/set map map_extra flags */ 761 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 762 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 763 764 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 765 const void *data, size_t size); 766 LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize); 767 768 /** 769 * @brief **bpf_map__is_internal()** tells the caller whether or not the 770 * passed map is a special map created by libbpf automatically for things like 771 * global variables, __ksym externs, Kconfig values, etc 772 * @param map the bpf_map 773 * @return true, if the map is an internal map; false, otherwise 774 */ 775 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 776 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 777 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 778 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 779 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 780 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 781 782 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 783 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 784 785 /** 786 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 787 * corresponding to provided key. 788 * @param map BPF map to lookup element in 789 * @param key pointer to memory containing bytes of the key used for lookup 790 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 791 * @param value pointer to memory in which looked up value will be stored 792 * @param value_sz size in byte of value data memory; it has to match BPF map 793 * definition's **value_size**. For per-CPU BPF maps value size has to be 794 * a product of BPF map value size and number of possible CPUs in the system 795 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 796 * per-CPU values value size has to be aligned up to closest 8 bytes for 797 * alignment reasons, so expected size is: `round_up(value_size, 8) 798 * * libbpf_num_possible_cpus()`. 799 * @flags extra flags passed to kernel for this operation 800 * @return 0, on success; negative error, otherwise 801 * 802 * **bpf_map__lookup_elem()** is high-level equivalent of 803 * **bpf_map_lookup_elem()** API with added check for key and value size. 804 */ 805 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 806 const void *key, size_t key_sz, 807 void *value, size_t value_sz, __u64 flags); 808 809 /** 810 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 811 * map that corresponds to provided key. 812 * @param map BPF map to insert to or update element in 813 * @param key pointer to memory containing bytes of the key 814 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 815 * @param value pointer to memory containing bytes of the value 816 * @param value_sz size in byte of value data memory; it has to match BPF map 817 * definition's **value_size**. For per-CPU BPF maps value size has to be 818 * a product of BPF map value size and number of possible CPUs in the system 819 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 820 * per-CPU values value size has to be aligned up to closest 8 bytes for 821 * alignment reasons, so expected size is: `round_up(value_size, 8) 822 * * libbpf_num_possible_cpus()`. 823 * @flags extra flags passed to kernel for this operation 824 * @return 0, on success; negative error, otherwise 825 * 826 * **bpf_map__update_elem()** is high-level equivalent of 827 * **bpf_map_update_elem()** API with added check for key and value size. 828 */ 829 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 830 const void *key, size_t key_sz, 831 const void *value, size_t value_sz, __u64 flags); 832 833 /** 834 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 835 * corresponds to provided key. 836 * @param map BPF map to delete element from 837 * @param key pointer to memory containing bytes of the key 838 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 839 * @flags extra flags passed to kernel for this operation 840 * @return 0, on success; negative error, otherwise 841 * 842 * **bpf_map__delete_elem()** is high-level equivalent of 843 * **bpf_map_delete_elem()** API with added check for key size. 844 */ 845 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 846 const void *key, size_t key_sz, __u64 flags); 847 848 /** 849 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 850 * corresponding to provided key and atomically delete it afterwards. 851 * @param map BPF map to lookup element in 852 * @param key pointer to memory containing bytes of the key used for lookup 853 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 854 * @param value pointer to memory in which looked up value will be stored 855 * @param value_sz size in byte of value data memory; it has to match BPF map 856 * definition's **value_size**. For per-CPU BPF maps value size has to be 857 * a product of BPF map value size and number of possible CPUs in the system 858 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 859 * per-CPU values value size has to be aligned up to closest 8 bytes for 860 * alignment reasons, so expected size is: `round_up(value_size, 8) 861 * * libbpf_num_possible_cpus()`. 862 * @flags extra flags passed to kernel for this operation 863 * @return 0, on success; negative error, otherwise 864 * 865 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 866 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 867 */ 868 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 869 const void *key, size_t key_sz, 870 void *value, size_t value_sz, __u64 flags); 871 872 /** 873 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 874 * fetching next key that follows current key. 875 * @param map BPF map to fetch next key from 876 * @param cur_key pointer to memory containing bytes of current key or NULL to 877 * fetch the first key 878 * @param next_key pointer to memory to write next key into 879 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 880 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 881 * negative error, otherwise 882 * 883 * **bpf_map__get_next_key()** is high-level equivalent of 884 * **bpf_map_get_next_key()** API with added check for key size. 885 */ 886 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 887 const void *cur_key, void *next_key, size_t key_sz); 888 889 struct bpf_xdp_set_link_opts { 890 size_t sz; 891 int old_fd; 892 size_t :0; 893 }; 894 #define bpf_xdp_set_link_opts__last_field old_fd 895 896 struct bpf_xdp_attach_opts { 897 size_t sz; 898 int old_prog_fd; 899 size_t :0; 900 }; 901 #define bpf_xdp_attach_opts__last_field old_prog_fd 902 903 struct bpf_xdp_query_opts { 904 size_t sz; 905 __u32 prog_id; /* output */ 906 __u32 drv_prog_id; /* output */ 907 __u32 hw_prog_id; /* output */ 908 __u32 skb_prog_id; /* output */ 909 __u8 attach_mode; /* output */ 910 size_t :0; 911 }; 912 #define bpf_xdp_query_opts__last_field attach_mode 913 914 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 915 const struct bpf_xdp_attach_opts *opts); 916 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 917 const struct bpf_xdp_attach_opts *opts); 918 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 919 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 920 921 /* TC related API */ 922 enum bpf_tc_attach_point { 923 BPF_TC_INGRESS = 1 << 0, 924 BPF_TC_EGRESS = 1 << 1, 925 BPF_TC_CUSTOM = 1 << 2, 926 }; 927 928 #define BPF_TC_PARENT(a, b) \ 929 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 930 931 enum bpf_tc_flags { 932 BPF_TC_F_REPLACE = 1 << 0, 933 }; 934 935 struct bpf_tc_hook { 936 size_t sz; 937 int ifindex; 938 enum bpf_tc_attach_point attach_point; 939 __u32 parent; 940 size_t :0; 941 }; 942 #define bpf_tc_hook__last_field parent 943 944 struct bpf_tc_opts { 945 size_t sz; 946 int prog_fd; 947 __u32 flags; 948 __u32 prog_id; 949 __u32 handle; 950 __u32 priority; 951 size_t :0; 952 }; 953 #define bpf_tc_opts__last_field priority 954 955 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 956 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 957 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 958 struct bpf_tc_opts *opts); 959 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 960 const struct bpf_tc_opts *opts); 961 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 962 struct bpf_tc_opts *opts); 963 964 /* Ring buffer APIs */ 965 struct ring_buffer; 966 967 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 968 969 struct ring_buffer_opts { 970 size_t sz; /* size of this struct, for forward/backward compatiblity */ 971 }; 972 973 #define ring_buffer_opts__last_field sz 974 975 LIBBPF_API struct ring_buffer * 976 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 977 const struct ring_buffer_opts *opts); 978 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 979 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 980 ring_buffer_sample_fn sample_cb, void *ctx); 981 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 982 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 983 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 984 985 /* Perf buffer APIs */ 986 struct perf_buffer; 987 988 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 989 void *data, __u32 size); 990 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 991 992 /* common use perf buffer options */ 993 struct perf_buffer_opts { 994 size_t sz; 995 }; 996 #define perf_buffer_opts__last_field sz 997 998 /** 999 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1000 * BPF_PERF_EVENT_ARRAY map 1001 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1002 * code to send data over to user-space 1003 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1004 * @param sample_cb function called on each received data record 1005 * @param lost_cb function called when record loss has occurred 1006 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1007 * @return a new instance of struct perf_buffer on success, NULL on error with 1008 * *errno* containing an error code 1009 */ 1010 LIBBPF_API struct perf_buffer * 1011 perf_buffer__new(int map_fd, size_t page_cnt, 1012 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1013 const struct perf_buffer_opts *opts); 1014 1015 enum bpf_perf_event_ret { 1016 LIBBPF_PERF_EVENT_DONE = 0, 1017 LIBBPF_PERF_EVENT_ERROR = -1, 1018 LIBBPF_PERF_EVENT_CONT = -2, 1019 }; 1020 1021 struct perf_event_header; 1022 1023 typedef enum bpf_perf_event_ret 1024 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1025 1026 /* raw perf buffer options, giving most power and control */ 1027 struct perf_buffer_raw_opts { 1028 size_t sz; 1029 long :0; 1030 long :0; 1031 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1032 * max_entries of given PERF_EVENT_ARRAY map) 1033 */ 1034 int cpu_cnt; 1035 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1036 int *cpus; 1037 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1038 int *map_keys; 1039 }; 1040 #define perf_buffer_raw_opts__last_field map_keys 1041 1042 struct perf_event_attr; 1043 1044 LIBBPF_API struct perf_buffer * 1045 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1046 perf_buffer_event_fn event_cb, void *ctx, 1047 const struct perf_buffer_raw_opts *opts); 1048 1049 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1050 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1051 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1052 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1053 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1054 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1055 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1056 1057 struct bpf_prog_linfo; 1058 struct bpf_prog_info; 1059 1060 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1061 LIBBPF_API struct bpf_prog_linfo * 1062 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1063 LIBBPF_API const struct bpf_line_info * 1064 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1065 __u64 addr, __u32 func_idx, __u32 nr_skip); 1066 LIBBPF_API const struct bpf_line_info * 1067 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1068 __u32 insn_off, __u32 nr_skip); 1069 1070 /* 1071 * Probe for supported system features 1072 * 1073 * Note that running many of these probes in a short amount of time can cause 1074 * the kernel to reach the maximal size of lockable memory allowed for the 1075 * user, causing subsequent probes to fail. In this case, the caller may want 1076 * to adjust that limit with setrlimit(). 1077 */ 1078 1079 /** 1080 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1081 * BPF programs of a given type. 1082 * @param prog_type BPF program type to detect kernel support for 1083 * @param opts reserved for future extensibility, should be NULL 1084 * @return 1, if given program type is supported; 0, if given program type is 1085 * not supported; negative error code if feature detection failed or can't be 1086 * performed 1087 * 1088 * Make sure the process has required set of CAP_* permissions (or runs as 1089 * root) when performing feature checking. 1090 */ 1091 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1092 /** 1093 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1094 * BPF maps of a given type. 1095 * @param map_type BPF map type to detect kernel support for 1096 * @param opts reserved for future extensibility, should be NULL 1097 * @return 1, if given map type is supported; 0, if given map type is 1098 * not supported; negative error code if feature detection failed or can't be 1099 * performed 1100 * 1101 * Make sure the process has required set of CAP_* permissions (or runs as 1102 * root) when performing feature checking. 1103 */ 1104 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1105 /** 1106 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1107 * use of a given BPF helper from specified BPF program type. 1108 * @param prog_type BPF program type used to check the support of BPF helper 1109 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1110 * @param opts reserved for future extensibility, should be NULL 1111 * @return 1, if given combination of program type and helper is supported; 0, 1112 * if the combination is not supported; negative error code if feature 1113 * detection for provided input arguments failed or can't be performed 1114 * 1115 * Make sure the process has required set of CAP_* permissions (or runs as 1116 * root) when performing feature checking. 1117 */ 1118 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1119 enum bpf_func_id helper_id, const void *opts); 1120 1121 /** 1122 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1123 * number of possible CPUs that the host kernel supports and expects. 1124 * @return number of possible CPUs; or error code on failure 1125 * 1126 * Example usage: 1127 * 1128 * int ncpus = libbpf_num_possible_cpus(); 1129 * if (ncpus < 0) { 1130 * // error handling 1131 * } 1132 * long values[ncpus]; 1133 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1134 */ 1135 LIBBPF_API int libbpf_num_possible_cpus(void); 1136 1137 struct bpf_map_skeleton { 1138 const char *name; 1139 struct bpf_map **map; 1140 void **mmaped; 1141 }; 1142 1143 struct bpf_prog_skeleton { 1144 const char *name; 1145 struct bpf_program **prog; 1146 struct bpf_link **link; 1147 }; 1148 1149 struct bpf_object_skeleton { 1150 size_t sz; /* size of this struct, for forward/backward compatibility */ 1151 1152 const char *name; 1153 const void *data; 1154 size_t data_sz; 1155 1156 struct bpf_object **obj; 1157 1158 int map_cnt; 1159 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1160 struct bpf_map_skeleton *maps; 1161 1162 int prog_cnt; 1163 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1164 struct bpf_prog_skeleton *progs; 1165 }; 1166 1167 LIBBPF_API int 1168 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1169 const struct bpf_object_open_opts *opts); 1170 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1171 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1172 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1173 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1174 1175 struct bpf_var_skeleton { 1176 const char *name; 1177 struct bpf_map **map; 1178 void **addr; 1179 }; 1180 1181 struct bpf_object_subskeleton { 1182 size_t sz; /* size of this struct, for forward/backward compatibility */ 1183 1184 const struct bpf_object *obj; 1185 1186 int map_cnt; 1187 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1188 struct bpf_map_skeleton *maps; 1189 1190 int prog_cnt; 1191 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1192 struct bpf_prog_skeleton *progs; 1193 1194 int var_cnt; 1195 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1196 struct bpf_var_skeleton *vars; 1197 }; 1198 1199 LIBBPF_API int 1200 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1201 LIBBPF_API void 1202 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1203 1204 struct gen_loader_opts { 1205 size_t sz; /* size of this struct, for forward/backward compatiblity */ 1206 const char *data; 1207 const char *insns; 1208 __u32 data_sz; 1209 __u32 insns_sz; 1210 }; 1211 1212 #define gen_loader_opts__last_field insns_sz 1213 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1214 struct gen_loader_opts *opts); 1215 1216 enum libbpf_tristate { 1217 TRI_NO = 0, 1218 TRI_YES = 1, 1219 TRI_MODULE = 2, 1220 }; 1221 1222 struct bpf_linker_opts { 1223 /* size of this struct, for forward/backward compatiblity */ 1224 size_t sz; 1225 }; 1226 #define bpf_linker_opts__last_field sz 1227 1228 struct bpf_linker_file_opts { 1229 /* size of this struct, for forward/backward compatiblity */ 1230 size_t sz; 1231 }; 1232 #define bpf_linker_file_opts__last_field sz 1233 1234 struct bpf_linker; 1235 1236 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1237 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1238 const char *filename, 1239 const struct bpf_linker_file_opts *opts); 1240 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1241 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1242 1243 /* 1244 * Custom handling of BPF program's SEC() definitions 1245 */ 1246 1247 struct bpf_prog_load_opts; /* defined in bpf.h */ 1248 1249 /* Called during bpf_object__open() for each recognized BPF program. Callback 1250 * can use various bpf_program__set_*() setters to adjust whatever properties 1251 * are necessary. 1252 */ 1253 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1254 1255 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1256 * into the kernel. Callback can adjust opts as necessary. 1257 */ 1258 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1259 struct bpf_prog_load_opts *opts, long cookie); 1260 1261 /* Called during skeleton attach or through bpf_program__attach(). If 1262 * auto-attach is not supported, callback should return 0 and set link to 1263 * NULL (it's not considered an error during skeleton attach, but it will be 1264 * an error for bpf_program__attach() calls). On error, error should be 1265 * returned directly and link set to NULL. On success, return 0 and set link 1266 * to a valid struct bpf_link. 1267 */ 1268 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1269 struct bpf_link **link); 1270 1271 struct libbpf_prog_handler_opts { 1272 /* size of this struct, for forward/backward compatiblity */ 1273 size_t sz; 1274 /* User-provided value that is passed to prog_setup_fn, 1275 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1276 * register one set of callbacks for multiple SEC() definitions and 1277 * still be able to distinguish them, if necessary. For example, 1278 * libbpf itself is using this to pass necessary flags (e.g., 1279 * sleepable flag) to a common internal SEC() handler. 1280 */ 1281 long cookie; 1282 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1283 * Callback is optional, pass NULL if it's not necessary. 1284 */ 1285 libbpf_prog_setup_fn_t prog_setup_fn; 1286 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1287 * Callback is optional, pass NULL if it's not necessary. 1288 */ 1289 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1290 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1291 * Callback is optional, pass NULL if it's not necessary. 1292 */ 1293 libbpf_prog_attach_fn_t prog_attach_fn; 1294 }; 1295 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1296 1297 /** 1298 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1299 * SEC() handler. 1300 * @param sec section prefix for which custom handler is registered 1301 * @param prog_type BPF program type associated with specified section 1302 * @param exp_attach_type Expected BPF attach type associated with specified section 1303 * @param opts optional cookie, callbacks, and other extra options 1304 * @return Non-negative handler ID is returned on success. This handler ID has 1305 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1306 * custom handler. Negative error code is returned on error. 1307 * 1308 * *sec* defines which SEC() definitions are handled by this custom handler 1309 * registration. *sec* can have few different forms: 1310 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1311 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1312 * in an error; 1313 * - if *sec* is of the form "abc/", proper SEC() form is 1314 * SEC("abc/something"), where acceptable "something" should be checked by 1315 * *prog_init_fn* callback, if there are additional restrictions; 1316 * - if *sec* is of the form "abc+", it will successfully match both 1317 * SEC("abc") and SEC("abc/whatever") forms; 1318 * - if *sec* is NULL, custom handler is registered for any BPF program that 1319 * doesn't match any of the registered (custom or libbpf's own) SEC() 1320 * handlers. There could be only one such generic custom handler registered 1321 * at any given time. 1322 * 1323 * All custom handlers (except the one with *sec* == NULL) are processed 1324 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1325 * SEC() handlers by registering custom ones for the same section prefix 1326 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1327 * handler). 1328 * 1329 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1330 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1331 * to ensure synchronization if there is a risk of running this API from 1332 * multiple threads simultaneously. 1333 */ 1334 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 1335 enum bpf_prog_type prog_type, 1336 enum bpf_attach_type exp_attach_type, 1337 const struct libbpf_prog_handler_opts *opts); 1338 /** 1339 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 1340 * custom BPF program SEC() handler. 1341 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 1342 * after successful registration 1343 * @return 0 on success, negative error code if handler isn't found 1344 * 1345 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1346 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1347 * to ensure synchronization if there is a risk of running this API from 1348 * multiple threads simultaneously. 1349 */ 1350 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 1351 1352 #ifdef __cplusplus 1353 } /* extern "C" */ 1354 #endif 1355 1356 #endif /* __LIBBPF_LIBBPF_H */ 1357