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