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0001 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 0002 0003 /* 0004 * Common eBPF ELF object loading operations. 0005 * 0006 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 0007 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 0008 * Copyright (C) 2015 Huawei Inc. 0009 */ 0010 #ifndef __LIBBPF_LIBBPF_H 0011 #define __LIBBPF_LIBBPF_H 0012 0013 #include <stdarg.h> 0014 #include <stdio.h> 0015 #include <stdint.h> 0016 #include <stdbool.h> 0017 #include <sys/types.h> // for size_t 0018 #include <linux/bpf.h> 0019 0020 #include "libbpf_common.h" 0021 #include "libbpf_legacy.h" 0022 0023 #ifdef __cplusplus 0024 extern "C" { 0025 #endif 0026 0027 LIBBPF_API __u32 libbpf_major_version(void); 0028 LIBBPF_API __u32 libbpf_minor_version(void); 0029 LIBBPF_API const char *libbpf_version_string(void); 0030 0031 enum libbpf_errno { 0032 __LIBBPF_ERRNO__START = 4000, 0033 0034 /* Something wrong in libelf */ 0035 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 0036 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 0037 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 0038 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 0039 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 0040 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 0041 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 0042 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 0043 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 0044 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 0045 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 0046 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 0047 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 0048 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 0049 __LIBBPF_ERRNO__END, 0050 }; 0051 0052 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 0053 0054 /** 0055 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type 0056 * value into a textual representation. 0057 * @param t The attach type. 0058 * @return Pointer to a static string identifying the attach type. NULL is 0059 * returned for unknown **bpf_attach_type** values. 0060 */ 0061 LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t); 0062 0063 /** 0064 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value 0065 * into a textual representation. 0066 * @param t The link type. 0067 * @return Pointer to a static string identifying the link type. NULL is 0068 * returned for unknown **bpf_link_type** values. 0069 */ 0070 LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t); 0071 0072 /** 0073 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value 0074 * into a textual representation. 0075 * @param t The map type. 0076 * @return Pointer to a static string identifying the map type. NULL is 0077 * returned for unknown **bpf_map_type** values. 0078 */ 0079 LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t); 0080 0081 /** 0082 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type 0083 * value into a textual representation. 0084 * @param t The program type. 0085 * @return Pointer to a static string identifying the program type. NULL is 0086 * returned for unknown **bpf_prog_type** values. 0087 */ 0088 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t); 0089 0090 enum libbpf_print_level { 0091 LIBBPF_WARN, 0092 LIBBPF_INFO, 0093 LIBBPF_DEBUG, 0094 }; 0095 0096 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, 0097 const char *, va_list ap); 0098 0099 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); 0100 0101 /* Hide internal to user */ 0102 struct bpf_object; 0103 0104 struct bpf_object_open_opts { 0105 /* size of this struct, for forward/backward compatibility */ 0106 size_t sz; 0107 /* object name override, if provided: 0108 * - for object open from file, this will override setting object 0109 * name from file path's base name; 0110 * - for object open from memory buffer, this will specify an object 0111 * name and will override default "<addr>-<buf-size>" name; 0112 */ 0113 const char *object_name; 0114 /* parse map definitions non-strictly, allowing extra attributes/data */ 0115 bool relaxed_maps; 0116 /* maps that set the 'pinning' attribute in their definition will have 0117 * their pin_path attribute set to a file in this directory, and be 0118 * auto-pinned to that path on load; defaults to "/sys/fs/bpf". 0119 */ 0120 const char *pin_root_path; 0121 long :0; 0122 /* Additional kernel config content that augments and overrides 0123 * system Kconfig for CONFIG_xxx externs. 0124 */ 0125 const char *kconfig; 0126 /* Path to the custom BTF to be used for BPF CO-RE relocations. 0127 * This custom BTF completely replaces the use of vmlinux BTF 0128 * for the purpose of CO-RE relocations. 0129 * NOTE: any other BPF feature (e.g., fentry/fexit programs, 0130 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. 0131 */ 0132 const char *btf_custom_path; 0133 /* Pointer to a buffer for storing kernel logs for applicable BPF 0134 * commands. Valid kernel_log_size has to be specified as well and are 0135 * passed-through to bpf() syscall. Keep in mind that kernel might 0136 * fail operation with -ENOSPC error if provided buffer is too small 0137 * to contain entire log output. 0138 * See the comment below for kernel_log_level for interaction between 0139 * log_buf and log_level settings. 0140 * 0141 * If specified, this log buffer will be passed for: 0142 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden 0143 * with bpf_program__set_log() on per-program level, to get 0144 * BPF verifier log output. 0145 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get 0146 * BTF sanity checking log. 0147 * 0148 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite 0149 * previous contents, so if you need more fine-grained control, set 0150 * per-program buffer with bpf_program__set_log_buf() to preserve each 0151 * individual program's verification log. Keep using kernel_log_buf 0152 * for BTF verification log, if necessary. 0153 */ 0154 char *kernel_log_buf; 0155 size_t kernel_log_size; 0156 /* 0157 * Log level can be set independently from log buffer. Log_level=0 0158 * means that libbpf will attempt loading BTF or program without any 0159 * logging requested, but will retry with either its own or custom log 0160 * buffer, if provided, and log_level=1 on any error. 0161 * And vice versa, setting log_level>0 will request BTF or prog 0162 * loading with verbose log from the first attempt (and as such also 0163 * for successfully loaded BTF or program), and the actual log buffer 0164 * could be either libbpf's own auto-allocated log buffer, if 0165 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. 0166 * If user didn't provide custom log buffer, libbpf will emit captured 0167 * logs through its print callback. 0168 */ 0169 __u32 kernel_log_level; 0170 0171 size_t :0; 0172 }; 0173 #define bpf_object_open_opts__last_field kernel_log_level 0174 0175 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 0176 0177 /** 0178 * @brief **bpf_object__open_file()** creates a bpf_object by opening 0179 * the BPF ELF object file pointed to by the passed path and loading it 0180 * into memory. 0181 * @param path BPF object file path 0182 * @param opts options for how to load the bpf object, this parameter is 0183 * optional and can be set to NULL 0184 * @return pointer to the new bpf_object; or NULL is returned on error, 0185 * error code is stored in errno 0186 */ 0187 LIBBPF_API struct bpf_object * 0188 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); 0189 0190 /** 0191 * @brief **bpf_object__open_mem()** creates a bpf_object by reading 0192 * the BPF objects raw bytes from a memory buffer containing a valid 0193 * BPF ELF object file. 0194 * @param obj_buf pointer to the buffer containing ELF file bytes 0195 * @param obj_buf_sz number of bytes in the buffer 0196 * @param opts options for how to load the bpf object 0197 * @return pointer to the new bpf_object; or NULL is returned on error, 0198 * error code is stored in errno 0199 */ 0200 LIBBPF_API struct bpf_object * 0201 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, 0202 const struct bpf_object_open_opts *opts); 0203 0204 /* Load/unload object into/from kernel */ 0205 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 0206 0207 LIBBPF_API void bpf_object__close(struct bpf_object *object); 0208 0209 /* pin_maps and unpin_maps can both be called with a NULL path, in which case 0210 * they will use the pin_path attribute of each map (and ignore all maps that 0211 * don't have a pin_path set). 0212 */ 0213 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); 0214 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, 0215 const char *path); 0216 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, 0217 const char *path); 0218 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, 0219 const char *path); 0220 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 0221 0222 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); 0223 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); 0224 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); 0225 0226 struct btf; 0227 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); 0228 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 0229 0230 LIBBPF_API struct bpf_program * 0231 bpf_object__find_program_by_name(const struct bpf_object *obj, 0232 const char *name); 0233 0234 LIBBPF_API int 0235 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 0236 enum bpf_attach_type *expected_attach_type); 0237 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 0238 enum bpf_attach_type *attach_type); 0239 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, 0240 enum bpf_attach_type attach_type); 0241 0242 /* Accessors of bpf_program */ 0243 struct bpf_program; 0244 0245 LIBBPF_API struct bpf_program * 0246 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); 0247 0248 #define bpf_object__for_each_program(pos, obj) \ 0249 for ((pos) = bpf_object__next_program((obj), NULL); \ 0250 (pos) != NULL; \ 0251 (pos) = bpf_object__next_program((obj), (pos))) 0252 0253 LIBBPF_API struct bpf_program * 0254 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); 0255 0256 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 0257 __u32 ifindex); 0258 0259 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); 0260 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); 0261 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); 0262 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); 0263 0264 struct bpf_insn; 0265 0266 /** 0267 * @brief **bpf_program__insns()** gives read-only access to BPF program's 0268 * underlying BPF instructions. 0269 * @param prog BPF program for which to return instructions 0270 * @return a pointer to an array of BPF instructions that belong to the 0271 * specified BPF program 0272 * 0273 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` 0274 * pointed to can be fetched using **bpf_program__insn_cnt()** API. 0275 * 0276 * Keep in mind, libbpf can modify and append/delete BPF program's 0277 * instructions as it processes BPF object file and prepares everything for 0278 * uploading into the kernel. So depending on the point in BPF object 0279 * lifetime, **bpf_program__insns()** can return different sets of 0280 * instructions. As an example, during BPF object load phase BPF program 0281 * instructions will be CO-RE-relocated, BPF subprograms instructions will be 0282 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions 0283 * returned before **bpf_object__load()** and after it might be quite 0284 * different. 0285 */ 0286 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); 0287 0288 /** 0289 * @brief **bpf_program__set_insns()** can set BPF program's underlying 0290 * BPF instructions. 0291 * 0292 * WARNING: This is a very advanced libbpf API and users need to know 0293 * what they are doing. This should be used from prog_prepare_load_fn 0294 * callback only. 0295 * 0296 * @param prog BPF program for which to return instructions 0297 * @param new_insns a pointer to an array of BPF instructions 0298 * @param new_insn_cnt number of `struct bpf_insn`'s that form 0299 * specified BPF program 0300 * @return 0, on success; negative error code, otherwise 0301 */ 0302 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, 0303 struct bpf_insn *new_insns, size_t new_insn_cnt); 0304 0305 /** 0306 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s 0307 * that form specified BPF program. 0308 * @param prog BPF program for which to return number of BPF instructions 0309 * 0310 * See **bpf_program__insns()** documentation for notes on how libbpf can 0311 * change instructions and their count during different phases of 0312 * **bpf_object** lifetime. 0313 */ 0314 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); 0315 0316 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); 0317 0318 /** 0319 * @brief **bpf_program__pin()** pins the BPF program to a file 0320 * in the BPF FS specified by a path. This increments the programs 0321 * reference count, allowing it to stay loaded after the process 0322 * which loaded it has exited. 0323 * 0324 * @param prog BPF program to pin, must already be loaded 0325 * @param path file path in a BPF file system 0326 * @return 0, on success; negative error code, otherwise 0327 */ 0328 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 0329 0330 /** 0331 * @brief **bpf_program__unpin()** unpins the BPF program from a file 0332 * in the BPFFS specified by a path. This decrements the programs 0333 * reference count. 0334 * 0335 * The file pinning the BPF program can also be unlinked by a different 0336 * process in which case this function will return an error. 0337 * 0338 * @param prog BPF program to unpin 0339 * @param path file path to the pin in a BPF file system 0340 * @return 0, on success; negative error code, otherwise 0341 */ 0342 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); 0343 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 0344 0345 struct bpf_link; 0346 0347 LIBBPF_API struct bpf_link *bpf_link__open(const char *path); 0348 LIBBPF_API int bpf_link__fd(const struct bpf_link *link); 0349 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); 0350 /** 0351 * @brief **bpf_link__pin()** pins the BPF link to a file 0352 * in the BPF FS specified by a path. This increments the links 0353 * reference count, allowing it to stay loaded after the process 0354 * which loaded it has exited. 0355 * 0356 * @param link BPF link to pin, must already be loaded 0357 * @param path file path in a BPF file system 0358 * @return 0, on success; negative error code, otherwise 0359 */ 0360 0361 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); 0362 0363 /** 0364 * @brief **bpf_link__unpin()** unpins the BPF link from a file 0365 * in the BPFFS specified by a path. This decrements the links 0366 * reference count. 0367 * 0368 * The file pinning the BPF link can also be unlinked by a different 0369 * process in which case this function will return an error. 0370 * 0371 * @param prog BPF program to unpin 0372 * @param path file path to the pin in a BPF file system 0373 * @return 0, on success; negative error code, otherwise 0374 */ 0375 LIBBPF_API int bpf_link__unpin(struct bpf_link *link); 0376 LIBBPF_API int bpf_link__update_program(struct bpf_link *link, 0377 struct bpf_program *prog); 0378 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); 0379 LIBBPF_API int bpf_link__detach(struct bpf_link *link); 0380 LIBBPF_API int bpf_link__destroy(struct bpf_link *link); 0381 0382 /** 0383 * @brief **bpf_program__attach()** is a generic function for attaching 0384 * a BPF program based on auto-detection of program type, attach type, 0385 * and extra paremeters, where applicable. 0386 * 0387 * @param prog BPF program to attach 0388 * @return Reference to the newly created BPF link; or NULL is returned on error, 0389 * error code is stored in errno 0390 * 0391 * This is supported for: 0392 * - kprobe/kretprobe (depends on SEC() definition) 0393 * - uprobe/uretprobe (depends on SEC() definition) 0394 * - tracepoint 0395 * - raw tracepoint 0396 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) 0397 */ 0398 LIBBPF_API struct bpf_link * 0399 bpf_program__attach(const struct bpf_program *prog); 0400 0401 struct bpf_perf_event_opts { 0402 /* size of this struct, for forward/backward compatiblity */ 0403 size_t sz; 0404 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0405 __u64 bpf_cookie; 0406 }; 0407 #define bpf_perf_event_opts__last_field bpf_cookie 0408 0409 LIBBPF_API struct bpf_link * 0410 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); 0411 0412 LIBBPF_API struct bpf_link * 0413 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, 0414 const struct bpf_perf_event_opts *opts); 0415 0416 struct bpf_kprobe_opts { 0417 /* size of this struct, for forward/backward compatiblity */ 0418 size_t sz; 0419 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0420 __u64 bpf_cookie; 0421 /* function's offset to install kprobe to */ 0422 size_t offset; 0423 /* kprobe is return probe */ 0424 bool retprobe; 0425 size_t :0; 0426 }; 0427 #define bpf_kprobe_opts__last_field retprobe 0428 0429 LIBBPF_API struct bpf_link * 0430 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, 0431 const char *func_name); 0432 LIBBPF_API struct bpf_link * 0433 bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 0434 const char *func_name, 0435 const struct bpf_kprobe_opts *opts); 0436 0437 struct bpf_kprobe_multi_opts { 0438 /* size of this struct, for forward/backward compatibility */ 0439 size_t sz; 0440 /* array of function symbols to attach */ 0441 const char **syms; 0442 /* array of function addresses to attach */ 0443 const unsigned long *addrs; 0444 /* array of user-provided values fetchable through bpf_get_attach_cookie */ 0445 const __u64 *cookies; 0446 /* number of elements in syms/addrs/cookies arrays */ 0447 size_t cnt; 0448 /* create return kprobes */ 0449 bool retprobe; 0450 size_t :0; 0451 }; 0452 0453 #define bpf_kprobe_multi_opts__last_field retprobe 0454 0455 LIBBPF_API struct bpf_link * 0456 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, 0457 const char *pattern, 0458 const struct bpf_kprobe_multi_opts *opts); 0459 0460 struct bpf_ksyscall_opts { 0461 /* size of this struct, for forward/backward compatiblity */ 0462 size_t sz; 0463 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0464 __u64 bpf_cookie; 0465 /* attach as return probe? */ 0466 bool retprobe; 0467 size_t :0; 0468 }; 0469 #define bpf_ksyscall_opts__last_field retprobe 0470 0471 /** 0472 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program 0473 * to kernel syscall handler of a specified syscall. Optionally it's possible 0474 * to request to install retprobe that will be triggered at syscall exit. It's 0475 * also possible to associate BPF cookie (though options). 0476 * 0477 * Libbpf automatically will determine correct full kernel function name, 0478 * which depending on system architecture and kernel version/configuration 0479 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will 0480 * attach specified program using kprobe/kretprobe mechanism. 0481 * 0482 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative 0483 * **SEC("ksyscall/<syscall>")** annotation of BPF programs. 0484 * 0485 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do 0486 * not handle all the calling convention quirks for mmap(), clone() and compat 0487 * syscalls. It also only attaches to "native" syscall interfaces. If host 0488 * system supports compat syscalls or defines 32-bit syscalls in 64-bit 0489 * kernel, such syscall interfaces won't be attached to by libbpf. 0490 * 0491 * These limitations may or may not change in the future. Therefore it is 0492 * recommended to use SEC("kprobe") for these syscalls or if working with 0493 * compat and 32-bit interfaces is required. 0494 * 0495 * @param prog BPF program to attach 0496 * @param syscall_name Symbolic name of the syscall (e.g., "bpf") 0497 * @param opts Additional options (see **struct bpf_ksyscall_opts**) 0498 * @return Reference to the newly created BPF link; or NULL is returned on 0499 * error, error code is stored in errno 0500 */ 0501 LIBBPF_API struct bpf_link * 0502 bpf_program__attach_ksyscall(const struct bpf_program *prog, 0503 const char *syscall_name, 0504 const struct bpf_ksyscall_opts *opts); 0505 0506 struct bpf_uprobe_opts { 0507 /* size of this struct, for forward/backward compatiblity */ 0508 size_t sz; 0509 /* offset of kernel reference counted USDT semaphore, added in 0510 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") 0511 */ 0512 size_t ref_ctr_offset; 0513 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0514 __u64 bpf_cookie; 0515 /* uprobe is return probe, invoked at function return time */ 0516 bool retprobe; 0517 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified 0518 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while 0519 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an 0520 * offset within a function, specify func_name and use func_offset argument to specify 0521 * offset within the function. Shared library functions must specify the shared library 0522 * binary_path. 0523 */ 0524 const char *func_name; 0525 size_t :0; 0526 }; 0527 #define bpf_uprobe_opts__last_field func_name 0528 0529 /** 0530 * @brief **bpf_program__attach_uprobe()** attaches a BPF program 0531 * to the userspace function which is found by binary path and 0532 * offset. You can optionally specify a particular proccess to attach 0533 * to. You can also optionally attach the program to the function 0534 * exit instead of entry. 0535 * 0536 * @param prog BPF program to attach 0537 * @param retprobe Attach to function exit 0538 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 0539 * -1 for all processes 0540 * @param binary_path Path to binary that contains the function symbol 0541 * @param func_offset Offset within the binary of the function symbol 0542 * @return Reference to the newly created BPF link; or NULL is returned on error, 0543 * error code is stored in errno 0544 */ 0545 LIBBPF_API struct bpf_link * 0546 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, 0547 pid_t pid, const char *binary_path, 0548 size_t func_offset); 0549 0550 /** 0551 * @brief **bpf_program__attach_uprobe_opts()** is just like 0552 * bpf_program__attach_uprobe() except with a options struct 0553 * for various configurations. 0554 * 0555 * @param prog BPF program to attach 0556 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 0557 * -1 for all processes 0558 * @param binary_path Path to binary that contains the function symbol 0559 * @param func_offset Offset within the binary of the function symbol 0560 * @param opts Options for altering program attachment 0561 * @return Reference to the newly created BPF link; or NULL is returned on error, 0562 * error code is stored in errno 0563 */ 0564 LIBBPF_API struct bpf_link * 0565 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, 0566 const char *binary_path, size_t func_offset, 0567 const struct bpf_uprobe_opts *opts); 0568 0569 struct bpf_usdt_opts { 0570 /* size of this struct, for forward/backward compatibility */ 0571 size_t sz; 0572 /* custom user-provided value accessible through usdt_cookie() */ 0573 __u64 usdt_cookie; 0574 size_t :0; 0575 }; 0576 #define bpf_usdt_opts__last_field usdt_cookie 0577 0578 /** 0579 * @brief **bpf_program__attach_usdt()** is just like 0580 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space 0581 * Statically Defined Tracepoint) attachment, instead of attaching to 0582 * user-space function entry or exit. 0583 * 0584 * @param prog BPF program to attach 0585 * @param pid Process ID to attach the uprobe to, 0 for self (own process), 0586 * -1 for all processes 0587 * @param binary_path Path to binary that contains provided USDT probe 0588 * @param usdt_provider USDT provider name 0589 * @param usdt_name USDT probe name 0590 * @param opts Options for altering program attachment 0591 * @return Reference to the newly created BPF link; or NULL is returned on error, 0592 * error code is stored in errno 0593 */ 0594 LIBBPF_API struct bpf_link * 0595 bpf_program__attach_usdt(const struct bpf_program *prog, 0596 pid_t pid, const char *binary_path, 0597 const char *usdt_provider, const char *usdt_name, 0598 const struct bpf_usdt_opts *opts); 0599 0600 struct bpf_tracepoint_opts { 0601 /* size of this struct, for forward/backward compatiblity */ 0602 size_t sz; 0603 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0604 __u64 bpf_cookie; 0605 }; 0606 #define bpf_tracepoint_opts__last_field bpf_cookie 0607 0608 LIBBPF_API struct bpf_link * 0609 bpf_program__attach_tracepoint(const struct bpf_program *prog, 0610 const char *tp_category, 0611 const char *tp_name); 0612 LIBBPF_API struct bpf_link * 0613 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, 0614 const char *tp_category, 0615 const char *tp_name, 0616 const struct bpf_tracepoint_opts *opts); 0617 0618 LIBBPF_API struct bpf_link * 0619 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, 0620 const char *tp_name); 0621 0622 struct bpf_trace_opts { 0623 /* size of this struct, for forward/backward compatibility */ 0624 size_t sz; 0625 /* custom user-provided value fetchable through bpf_get_attach_cookie() */ 0626 __u64 cookie; 0627 }; 0628 #define bpf_trace_opts__last_field cookie 0629 0630 LIBBPF_API struct bpf_link * 0631 bpf_program__attach_trace(const struct bpf_program *prog); 0632 LIBBPF_API struct bpf_link * 0633 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); 0634 0635 LIBBPF_API struct bpf_link * 0636 bpf_program__attach_lsm(const struct bpf_program *prog); 0637 LIBBPF_API struct bpf_link * 0638 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); 0639 LIBBPF_API struct bpf_link * 0640 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); 0641 LIBBPF_API struct bpf_link * 0642 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); 0643 LIBBPF_API struct bpf_link * 0644 bpf_program__attach_freplace(const struct bpf_program *prog, 0645 int target_fd, const char *attach_func_name); 0646 0647 struct bpf_map; 0648 0649 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); 0650 0651 struct bpf_iter_attach_opts { 0652 size_t sz; /* size of this struct for forward/backward compatibility */ 0653 union bpf_iter_link_info *link_info; 0654 __u32 link_info_len; 0655 }; 0656 #define bpf_iter_attach_opts__last_field link_info_len 0657 0658 LIBBPF_API struct bpf_link * 0659 bpf_program__attach_iter(const struct bpf_program *prog, 0660 const struct bpf_iter_attach_opts *opts); 0661 0662 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); 0663 0664 /** 0665 * @brief **bpf_program__set_type()** sets the program 0666 * type of the passed BPF program. 0667 * @param prog BPF program to set the program type for 0668 * @param type program type to set the BPF map to have 0669 * @return error code; or 0 if no error. An error occurs 0670 * if the object is already loaded. 0671 * 0672 * This must be called before the BPF object is loaded, 0673 * otherwise it has no effect and an error is returned. 0674 */ 0675 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, 0676 enum bpf_prog_type type); 0677 0678 LIBBPF_API enum bpf_attach_type 0679 bpf_program__expected_attach_type(const struct bpf_program *prog); 0680 0681 /** 0682 * @brief **bpf_program__set_expected_attach_type()** sets the 0683 * attach type of the passed BPF program. This is used for 0684 * auto-detection of attachment when programs are loaded. 0685 * @param prog BPF program to set the attach type for 0686 * @param type attach type to set the BPF map to have 0687 * @return error code; or 0 if no error. An error occurs 0688 * if the object is already loaded. 0689 * 0690 * This must be called before the BPF object is loaded, 0691 * otherwise it has no effect and an error is returned. 0692 */ 0693 LIBBPF_API int 0694 bpf_program__set_expected_attach_type(struct bpf_program *prog, 0695 enum bpf_attach_type type); 0696 0697 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); 0698 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); 0699 0700 /* Per-program log level and log buffer getters/setters. 0701 * See bpf_object_open_opts comments regarding log_level and log_buf 0702 * interactions. 0703 */ 0704 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); 0705 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); 0706 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); 0707 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); 0708 0709 /** 0710 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target 0711 * for supported BPF program types: 0712 * - BTF-aware raw tracepoints (tp_btf); 0713 * - fentry/fexit/fmod_ret; 0714 * - lsm; 0715 * - freplace. 0716 * @param prog BPF program to set the attach type for 0717 * @param type attach type to set the BPF map to have 0718 * @return error code; or 0 if no error occurred. 0719 */ 0720 LIBBPF_API int 0721 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, 0722 const char *attach_func_name); 0723 0724 /** 0725 * @brief **bpf_object__find_map_by_name()** returns BPF map of 0726 * the given name, if it exists within the passed BPF object 0727 * @param obj BPF object 0728 * @param name name of the BPF map 0729 * @return BPF map instance, if such map exists within the BPF object; 0730 * or NULL otherwise. 0731 */ 0732 LIBBPF_API struct bpf_map * 0733 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); 0734 0735 LIBBPF_API int 0736 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); 0737 0738 LIBBPF_API struct bpf_map * 0739 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); 0740 0741 #define bpf_object__for_each_map(pos, obj) \ 0742 for ((pos) = bpf_object__next_map((obj), NULL); \ 0743 (pos) != NULL; \ 0744 (pos) = bpf_object__next_map((obj), (pos))) 0745 #define bpf_map__for_each bpf_object__for_each_map 0746 0747 LIBBPF_API struct bpf_map * 0748 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); 0749 0750 /** 0751 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create 0752 * BPF map during BPF object load phase. 0753 * @param map the BPF map instance 0754 * @param autocreate whether to create BPF map during BPF object load 0755 * @return 0 on success; -EBUSY if BPF object was already loaded 0756 * 0757 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating 0758 * BPF map. By default, libbpf will attempt to create every single BPF map 0759 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall 0760 * and fill in map FD in BPF instructions. 0761 * 0762 * This API allows to opt-out of this process for specific map instance. This 0763 * can be useful if host kernel doesn't support such BPF map type or used 0764 * combination of flags and user application wants to avoid creating such 0765 * a map in the first place. User is still responsible to make sure that their 0766 * BPF-side code that expects to use such missing BPF map is recognized by BPF 0767 * verifier as dead code, otherwise BPF verifier will reject such BPF program. 0768 */ 0769 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); 0770 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); 0771 0772 /** 0773 * @brief **bpf_map__fd()** gets the file descriptor of the passed 0774 * BPF map 0775 * @param map the BPF map instance 0776 * @return the file descriptor; or -EINVAL in case of an error 0777 */ 0778 LIBBPF_API int bpf_map__fd(const struct bpf_map *map); 0779 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 0780 /* get map name */ 0781 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); 0782 /* get/set map type */ 0783 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); 0784 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); 0785 /* get/set map size (max_entries) */ 0786 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); 0787 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); 0788 /* get/set map flags */ 0789 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); 0790 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); 0791 /* get/set map NUMA node */ 0792 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); 0793 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); 0794 /* get/set map key size */ 0795 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); 0796 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); 0797 /* get/set map value size */ 0798 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); 0799 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); 0800 /* get map key/value BTF type IDs */ 0801 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 0802 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 0803 /* get/set map if_index */ 0804 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); 0805 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 0806 /* get/set map map_extra flags */ 0807 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); 0808 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); 0809 0810 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, 0811 const void *data, size_t size); 0812 LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize); 0813 0814 /** 0815 * @brief **bpf_map__is_internal()** tells the caller whether or not the 0816 * passed map is a special map created by libbpf automatically for things like 0817 * global variables, __ksym externs, Kconfig values, etc 0818 * @param map the bpf_map 0819 * @return true, if the map is an internal map; false, otherwise 0820 */ 0821 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); 0822 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); 0823 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); 0824 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); 0825 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 0826 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); 0827 0828 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); 0829 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); 0830 0831 /** 0832 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value 0833 * corresponding to provided key. 0834 * @param map BPF map to lookup element in 0835 * @param key pointer to memory containing bytes of the key used for lookup 0836 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 0837 * @param value pointer to memory in which looked up value will be stored 0838 * @param value_sz size in byte of value data memory; it has to match BPF map 0839 * definition's **value_size**. For per-CPU BPF maps value size has to be 0840 * a product of BPF map value size and number of possible CPUs in the system 0841 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 0842 * per-CPU values value size has to be aligned up to closest 8 bytes for 0843 * alignment reasons, so expected size is: `round_up(value_size, 8) 0844 * * libbpf_num_possible_cpus()`. 0845 * @flags extra flags passed to kernel for this operation 0846 * @return 0, on success; negative error, otherwise 0847 * 0848 * **bpf_map__lookup_elem()** is high-level equivalent of 0849 * **bpf_map_lookup_elem()** API with added check for key and value size. 0850 */ 0851 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, 0852 const void *key, size_t key_sz, 0853 void *value, size_t value_sz, __u64 flags); 0854 0855 /** 0856 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF 0857 * map that corresponds to provided key. 0858 * @param map BPF map to insert to or update element in 0859 * @param key pointer to memory containing bytes of the key 0860 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 0861 * @param value pointer to memory containing bytes of the value 0862 * @param value_sz size in byte of value data memory; it has to match BPF map 0863 * definition's **value_size**. For per-CPU BPF maps value size has to be 0864 * a product of BPF map value size and number of possible CPUs in the system 0865 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 0866 * per-CPU values value size has to be aligned up to closest 8 bytes for 0867 * alignment reasons, so expected size is: `round_up(value_size, 8) 0868 * * libbpf_num_possible_cpus()`. 0869 * @flags extra flags passed to kernel for this operation 0870 * @return 0, on success; negative error, otherwise 0871 * 0872 * **bpf_map__update_elem()** is high-level equivalent of 0873 * **bpf_map_update_elem()** API with added check for key and value size. 0874 */ 0875 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, 0876 const void *key, size_t key_sz, 0877 const void *value, size_t value_sz, __u64 flags); 0878 0879 /** 0880 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that 0881 * corresponds to provided key. 0882 * @param map BPF map to delete element from 0883 * @param key pointer to memory containing bytes of the key 0884 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 0885 * @flags extra flags passed to kernel for this operation 0886 * @return 0, on success; negative error, otherwise 0887 * 0888 * **bpf_map__delete_elem()** is high-level equivalent of 0889 * **bpf_map_delete_elem()** API with added check for key size. 0890 */ 0891 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, 0892 const void *key, size_t key_sz, __u64 flags); 0893 0894 /** 0895 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value 0896 * corresponding to provided key and atomically delete it afterwards. 0897 * @param map BPF map to lookup element in 0898 * @param key pointer to memory containing bytes of the key used for lookup 0899 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 0900 * @param value pointer to memory in which looked up value will be stored 0901 * @param value_sz size in byte of value data memory; it has to match BPF map 0902 * definition's **value_size**. For per-CPU BPF maps value size has to be 0903 * a product of BPF map value size and number of possible CPUs in the system 0904 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for 0905 * per-CPU values value size has to be aligned up to closest 8 bytes for 0906 * alignment reasons, so expected size is: `round_up(value_size, 8) 0907 * * libbpf_num_possible_cpus()`. 0908 * @flags extra flags passed to kernel for this operation 0909 * @return 0, on success; negative error, otherwise 0910 * 0911 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of 0912 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. 0913 */ 0914 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, 0915 const void *key, size_t key_sz, 0916 void *value, size_t value_sz, __u64 flags); 0917 0918 /** 0919 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by 0920 * fetching next key that follows current key. 0921 * @param map BPF map to fetch next key from 0922 * @param cur_key pointer to memory containing bytes of current key or NULL to 0923 * fetch the first key 0924 * @param next_key pointer to memory to write next key into 0925 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** 0926 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; 0927 * negative error, otherwise 0928 * 0929 * **bpf_map__get_next_key()** is high-level equivalent of 0930 * **bpf_map_get_next_key()** API with added check for key size. 0931 */ 0932 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, 0933 const void *cur_key, void *next_key, size_t key_sz); 0934 0935 struct bpf_xdp_set_link_opts { 0936 size_t sz; 0937 int old_fd; 0938 size_t :0; 0939 }; 0940 #define bpf_xdp_set_link_opts__last_field old_fd 0941 0942 struct bpf_xdp_attach_opts { 0943 size_t sz; 0944 int old_prog_fd; 0945 size_t :0; 0946 }; 0947 #define bpf_xdp_attach_opts__last_field old_prog_fd 0948 0949 struct bpf_xdp_query_opts { 0950 size_t sz; 0951 __u32 prog_id; /* output */ 0952 __u32 drv_prog_id; /* output */ 0953 __u32 hw_prog_id; /* output */ 0954 __u32 skb_prog_id; /* output */ 0955 __u8 attach_mode; /* output */ 0956 size_t :0; 0957 }; 0958 #define bpf_xdp_query_opts__last_field attach_mode 0959 0960 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, 0961 const struct bpf_xdp_attach_opts *opts); 0962 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, 0963 const struct bpf_xdp_attach_opts *opts); 0964 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); 0965 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); 0966 0967 /* TC related API */ 0968 enum bpf_tc_attach_point { 0969 BPF_TC_INGRESS = 1 << 0, 0970 BPF_TC_EGRESS = 1 << 1, 0971 BPF_TC_CUSTOM = 1 << 2, 0972 }; 0973 0974 #define BPF_TC_PARENT(a, b) \ 0975 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) 0976 0977 enum bpf_tc_flags { 0978 BPF_TC_F_REPLACE = 1 << 0, 0979 }; 0980 0981 struct bpf_tc_hook { 0982 size_t sz; 0983 int ifindex; 0984 enum bpf_tc_attach_point attach_point; 0985 __u32 parent; 0986 size_t :0; 0987 }; 0988 #define bpf_tc_hook__last_field parent 0989 0990 struct bpf_tc_opts { 0991 size_t sz; 0992 int prog_fd; 0993 __u32 flags; 0994 __u32 prog_id; 0995 __u32 handle; 0996 __u32 priority; 0997 size_t :0; 0998 }; 0999 #define bpf_tc_opts__last_field priority 1000 1001 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); 1002 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); 1003 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, 1004 struct bpf_tc_opts *opts); 1005 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, 1006 const struct bpf_tc_opts *opts); 1007 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, 1008 struct bpf_tc_opts *opts); 1009 1010 /* Ring buffer APIs */ 1011 struct ring_buffer; 1012 1013 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); 1014 1015 struct ring_buffer_opts { 1016 size_t sz; /* size of this struct, for forward/backward compatiblity */ 1017 }; 1018 1019 #define ring_buffer_opts__last_field sz 1020 1021 LIBBPF_API struct ring_buffer * 1022 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, 1023 const struct ring_buffer_opts *opts); 1024 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); 1025 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, 1026 ring_buffer_sample_fn sample_cb, void *ctx); 1027 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); 1028 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); 1029 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); 1030 1031 /* Perf buffer APIs */ 1032 struct perf_buffer; 1033 1034 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, 1035 void *data, __u32 size); 1036 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); 1037 1038 /* common use perf buffer options */ 1039 struct perf_buffer_opts { 1040 size_t sz; 1041 }; 1042 #define perf_buffer_opts__last_field sz 1043 1044 /** 1045 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified 1046 * BPF_PERF_EVENT_ARRAY map 1047 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF 1048 * code to send data over to user-space 1049 * @param page_cnt number of memory pages allocated for each per-CPU buffer 1050 * @param sample_cb function called on each received data record 1051 * @param lost_cb function called when record loss has occurred 1052 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* 1053 * @return a new instance of struct perf_buffer on success, NULL on error with 1054 * *errno* containing an error code 1055 */ 1056 LIBBPF_API struct perf_buffer * 1057 perf_buffer__new(int map_fd, size_t page_cnt, 1058 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, 1059 const struct perf_buffer_opts *opts); 1060 1061 enum bpf_perf_event_ret { 1062 LIBBPF_PERF_EVENT_DONE = 0, 1063 LIBBPF_PERF_EVENT_ERROR = -1, 1064 LIBBPF_PERF_EVENT_CONT = -2, 1065 }; 1066 1067 struct perf_event_header; 1068 1069 typedef enum bpf_perf_event_ret 1070 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); 1071 1072 /* raw perf buffer options, giving most power and control */ 1073 struct perf_buffer_raw_opts { 1074 size_t sz; 1075 long :0; 1076 long :0; 1077 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of 1078 * max_entries of given PERF_EVENT_ARRAY map) 1079 */ 1080 int cpu_cnt; 1081 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ 1082 int *cpus; 1083 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ 1084 int *map_keys; 1085 }; 1086 #define perf_buffer_raw_opts__last_field map_keys 1087 1088 struct perf_event_attr; 1089 1090 LIBBPF_API struct perf_buffer * 1091 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, 1092 perf_buffer_event_fn event_cb, void *ctx, 1093 const struct perf_buffer_raw_opts *opts); 1094 1095 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); 1096 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); 1097 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); 1098 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); 1099 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); 1100 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); 1101 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 1102 /** 1103 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying 1104 * memory region of the ring buffer. 1105 * This ring buffer can be used to implement a custom events consumer. 1106 * The ring buffer starts with the *struct perf_event_mmap_page*, which 1107 * holds the ring buffer managment fields, when accessing the header 1108 * structure it's important to be SMP aware. 1109 * You can refer to *perf_event_read_simple* for a simple example. 1110 * @param pb the perf buffer structure 1111 * @param buf_idx the buffer index to retreive 1112 * @param buf (out) gets the base pointer of the mmap()'ed memory 1113 * @param buf_size (out) gets the size of the mmap()'ed region 1114 * @return 0 on success, negative error code for failure 1115 */ 1116 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, 1117 size_t *buf_size); 1118 1119 struct bpf_prog_linfo; 1120 struct bpf_prog_info; 1121 1122 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); 1123 LIBBPF_API struct bpf_prog_linfo * 1124 bpf_prog_linfo__new(const struct bpf_prog_info *info); 1125 LIBBPF_API const struct bpf_line_info * 1126 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, 1127 __u64 addr, __u32 func_idx, __u32 nr_skip); 1128 LIBBPF_API const struct bpf_line_info * 1129 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, 1130 __u32 insn_off, __u32 nr_skip); 1131 1132 /* 1133 * Probe for supported system features 1134 * 1135 * Note that running many of these probes in a short amount of time can cause 1136 * the kernel to reach the maximal size of lockable memory allowed for the 1137 * user, causing subsequent probes to fail. In this case, the caller may want 1138 * to adjust that limit with setrlimit(). 1139 */ 1140 1141 /** 1142 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports 1143 * BPF programs of a given type. 1144 * @param prog_type BPF program type to detect kernel support for 1145 * @param opts reserved for future extensibility, should be NULL 1146 * @return 1, if given program type is supported; 0, if given program type is 1147 * not supported; negative error code if feature detection failed or can't be 1148 * performed 1149 * 1150 * Make sure the process has required set of CAP_* permissions (or runs as 1151 * root) when performing feature checking. 1152 */ 1153 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); 1154 /** 1155 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports 1156 * BPF maps of a given type. 1157 * @param map_type BPF map type to detect kernel support for 1158 * @param opts reserved for future extensibility, should be NULL 1159 * @return 1, if given map type is supported; 0, if given map type is 1160 * not supported; negative error code if feature detection failed or can't be 1161 * performed 1162 * 1163 * Make sure the process has required set of CAP_* permissions (or runs as 1164 * root) when performing feature checking. 1165 */ 1166 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); 1167 /** 1168 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the 1169 * use of a given BPF helper from specified BPF program type. 1170 * @param prog_type BPF program type used to check the support of BPF helper 1171 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for 1172 * @param opts reserved for future extensibility, should be NULL 1173 * @return 1, if given combination of program type and helper is supported; 0, 1174 * if the combination is not supported; negative error code if feature 1175 * detection for provided input arguments failed or can't be performed 1176 * 1177 * Make sure the process has required set of CAP_* permissions (or runs as 1178 * root) when performing feature checking. 1179 */ 1180 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, 1181 enum bpf_func_id helper_id, const void *opts); 1182 1183 /** 1184 * @brief **libbpf_num_possible_cpus()** is a helper function to get the 1185 * number of possible CPUs that the host kernel supports and expects. 1186 * @return number of possible CPUs; or error code on failure 1187 * 1188 * Example usage: 1189 * 1190 * int ncpus = libbpf_num_possible_cpus(); 1191 * if (ncpus < 0) { 1192 * // error handling 1193 * } 1194 * long values[ncpus]; 1195 * bpf_map_lookup_elem(per_cpu_map_fd, key, values); 1196 */ 1197 LIBBPF_API int libbpf_num_possible_cpus(void); 1198 1199 struct bpf_map_skeleton { 1200 const char *name; 1201 struct bpf_map **map; 1202 void **mmaped; 1203 }; 1204 1205 struct bpf_prog_skeleton { 1206 const char *name; 1207 struct bpf_program **prog; 1208 struct bpf_link **link; 1209 }; 1210 1211 struct bpf_object_skeleton { 1212 size_t sz; /* size of this struct, for forward/backward compatibility */ 1213 1214 const char *name; 1215 const void *data; 1216 size_t data_sz; 1217 1218 struct bpf_object **obj; 1219 1220 int map_cnt; 1221 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1222 struct bpf_map_skeleton *maps; 1223 1224 int prog_cnt; 1225 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1226 struct bpf_prog_skeleton *progs; 1227 }; 1228 1229 LIBBPF_API int 1230 bpf_object__open_skeleton(struct bpf_object_skeleton *s, 1231 const struct bpf_object_open_opts *opts); 1232 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); 1233 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); 1234 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); 1235 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); 1236 1237 struct bpf_var_skeleton { 1238 const char *name; 1239 struct bpf_map **map; 1240 void **addr; 1241 }; 1242 1243 struct bpf_object_subskeleton { 1244 size_t sz; /* size of this struct, for forward/backward compatibility */ 1245 1246 const struct bpf_object *obj; 1247 1248 int map_cnt; 1249 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ 1250 struct bpf_map_skeleton *maps; 1251 1252 int prog_cnt; 1253 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ 1254 struct bpf_prog_skeleton *progs; 1255 1256 int var_cnt; 1257 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ 1258 struct bpf_var_skeleton *vars; 1259 }; 1260 1261 LIBBPF_API int 1262 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); 1263 LIBBPF_API void 1264 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); 1265 1266 struct gen_loader_opts { 1267 size_t sz; /* size of this struct, for forward/backward compatiblity */ 1268 const char *data; 1269 const char *insns; 1270 __u32 data_sz; 1271 __u32 insns_sz; 1272 }; 1273 1274 #define gen_loader_opts__last_field insns_sz 1275 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, 1276 struct gen_loader_opts *opts); 1277 1278 enum libbpf_tristate { 1279 TRI_NO = 0, 1280 TRI_YES = 1, 1281 TRI_MODULE = 2, 1282 }; 1283 1284 struct bpf_linker_opts { 1285 /* size of this struct, for forward/backward compatiblity */ 1286 size_t sz; 1287 }; 1288 #define bpf_linker_opts__last_field sz 1289 1290 struct bpf_linker_file_opts { 1291 /* size of this struct, for forward/backward compatiblity */ 1292 size_t sz; 1293 }; 1294 #define bpf_linker_file_opts__last_field sz 1295 1296 struct bpf_linker; 1297 1298 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); 1299 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, 1300 const char *filename, 1301 const struct bpf_linker_file_opts *opts); 1302 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); 1303 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); 1304 1305 /* 1306 * Custom handling of BPF program's SEC() definitions 1307 */ 1308 1309 struct bpf_prog_load_opts; /* defined in bpf.h */ 1310 1311 /* Called during bpf_object__open() for each recognized BPF program. Callback 1312 * can use various bpf_program__set_*() setters to adjust whatever properties 1313 * are necessary. 1314 */ 1315 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); 1316 1317 /* Called right before libbpf performs bpf_prog_load() to load BPF program 1318 * into the kernel. Callback can adjust opts as necessary. 1319 */ 1320 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, 1321 struct bpf_prog_load_opts *opts, long cookie); 1322 1323 /* Called during skeleton attach or through bpf_program__attach(). If 1324 * auto-attach is not supported, callback should return 0 and set link to 1325 * NULL (it's not considered an error during skeleton attach, but it will be 1326 * an error for bpf_program__attach() calls). On error, error should be 1327 * returned directly and link set to NULL. On success, return 0 and set link 1328 * to a valid struct bpf_link. 1329 */ 1330 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, 1331 struct bpf_link **link); 1332 1333 struct libbpf_prog_handler_opts { 1334 /* size of this struct, for forward/backward compatiblity */ 1335 size_t sz; 1336 /* User-provided value that is passed to prog_setup_fn, 1337 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to 1338 * register one set of callbacks for multiple SEC() definitions and 1339 * still be able to distinguish them, if necessary. For example, 1340 * libbpf itself is using this to pass necessary flags (e.g., 1341 * sleepable flag) to a common internal SEC() handler. 1342 */ 1343 long cookie; 1344 /* BPF program initialization callback (see libbpf_prog_setup_fn_t). 1345 * Callback is optional, pass NULL if it's not necessary. 1346 */ 1347 libbpf_prog_setup_fn_t prog_setup_fn; 1348 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). 1349 * Callback is optional, pass NULL if it's not necessary. 1350 */ 1351 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; 1352 /* BPF program attach callback (see libbpf_prog_attach_fn_t). 1353 * Callback is optional, pass NULL if it's not necessary. 1354 */ 1355 libbpf_prog_attach_fn_t prog_attach_fn; 1356 }; 1357 #define libbpf_prog_handler_opts__last_field prog_attach_fn 1358 1359 /** 1360 * @brief **libbpf_register_prog_handler()** registers a custom BPF program 1361 * SEC() handler. 1362 * @param sec section prefix for which custom handler is registered 1363 * @param prog_type BPF program type associated with specified section 1364 * @param exp_attach_type Expected BPF attach type associated with specified section 1365 * @param opts optional cookie, callbacks, and other extra options 1366 * @return Non-negative handler ID is returned on success. This handler ID has 1367 * to be passed to *libbpf_unregister_prog_handler()* to unregister such 1368 * custom handler. Negative error code is returned on error. 1369 * 1370 * *sec* defines which SEC() definitions are handled by this custom handler 1371 * registration. *sec* can have few different forms: 1372 * - if *sec* is just a plain string (e.g., "abc"), it will match only 1373 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result 1374 * in an error; 1375 * - if *sec* is of the form "abc/", proper SEC() form is 1376 * SEC("abc/something"), where acceptable "something" should be checked by 1377 * *prog_init_fn* callback, if there are additional restrictions; 1378 * - if *sec* is of the form "abc+", it will successfully match both 1379 * SEC("abc") and SEC("abc/whatever") forms; 1380 * - if *sec* is NULL, custom handler is registered for any BPF program that 1381 * doesn't match any of the registered (custom or libbpf's own) SEC() 1382 * handlers. There could be only one such generic custom handler registered 1383 * at any given time. 1384 * 1385 * All custom handlers (except the one with *sec* == NULL) are processed 1386 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's 1387 * SEC() handlers by registering custom ones for the same section prefix 1388 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") 1389 * handler). 1390 * 1391 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1392 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1393 * to ensure synchronization if there is a risk of running this API from 1394 * multiple threads simultaneously. 1395 */ 1396 LIBBPF_API int libbpf_register_prog_handler(const char *sec, 1397 enum bpf_prog_type prog_type, 1398 enum bpf_attach_type exp_attach_type, 1399 const struct libbpf_prog_handler_opts *opts); 1400 /** 1401 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered 1402 * custom BPF program SEC() handler. 1403 * @param handler_id handler ID returned by *libbpf_register_prog_handler()* 1404 * after successful registration 1405 * @return 0 on success, negative error code if handler isn't found 1406 * 1407 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), 1408 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs 1409 * to ensure synchronization if there is a risk of running this API from 1410 * multiple threads simultaneously. 1411 */ 1412 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); 1413 1414 #ifdef __cplusplus 1415 } /* extern "C" */ 1416 #endif 1417 1418 #endif /* __LIBBPF_LIBBPF_H */
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