/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ /* * Common eBPF ELF object loading operations. * * Copyright (C) 2013-2015 Alexei Starovoitov * Copyright (C) 2015 Wang Nan * Copyright (C) 2015 Huawei Inc. */ #ifndef __LIBBPF_LIBBPF_H #define __LIBBPF_LIBBPF_H #include #include #include #include #include // for size_t #include #include "libbpf_common.h" #include "libbpf_legacy.h" #ifdef __cplusplus extern "C" { #endif LIBBPF_API __u32 libbpf_major_version(void); LIBBPF_API __u32 libbpf_minor_version(void); LIBBPF_API const char *libbpf_version_string(void); enum libbpf_errno { __LIBBPF_ERRNO__START = 4000, /* Something wrong in libelf */ LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ LIBBPF_ERRNO__RELOC, /* Relocation failed */ LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ LIBBPF_ERRNO__PROG2BIG, /* Program too big */ LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ __LIBBPF_ERRNO__END, }; LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); /** * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type * value into a textual representation. * @param t The attach type. * @return Pointer to a static string identifying the attach type. NULL is * returned for unknown **bpf_attach_type** values. */ LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t); /** * @brief **libbpf_bpf_link_type_str()** converts the provided link type value * into a textual representation. * @param t The link type. * @return Pointer to a static string identifying the link type. NULL is * returned for unknown **bpf_link_type** values. */ LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t); /** * @brief **libbpf_bpf_map_type_str()** converts the provided map type value * into a textual representation. * @param t The map type. * @return Pointer to a static string identifying the map type. NULL is * returned for unknown **bpf_map_type** values. */ LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t); /** * @brief **libbpf_bpf_prog_type_str()** converts the provided program type * value into a textual representation. * @param t The program type. * @return Pointer to a static string identifying the program type. NULL is * returned for unknown **bpf_prog_type** values. */ LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t); enum libbpf_print_level { LIBBPF_WARN, LIBBPF_INFO, LIBBPF_DEBUG, }; typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level, const char *, va_list ap); /** * @brief **libbpf_set_print()** sets user-provided log callback function to * be used for libbpf warnings and informational messages. If the user callback * is not set, messages are logged to stderr by default. The verbosity of these * messages can be controlled by setting the environment variable * LIBBPF_LOG_LEVEL to either warn, info, or debug. * @param fn The log print function. If NULL, libbpf won't print anything. * @return Pointer to old print function. * * This function is thread-safe. */ LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn); /* Hide internal to user */ struct bpf_object; struct bpf_object_open_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* object name override, if provided: * - for object open from file, this will override setting object * name from file path's base name; * - for object open from memory buffer, this will specify an object * name and will override default "-" name; */ const char *object_name; /* parse map definitions non-strictly, allowing extra attributes/data */ bool relaxed_maps; /* maps that set the 'pinning' attribute in their definition will have * their pin_path attribute set to a file in this directory, and be * auto-pinned to that path on load; defaults to "/sys/fs/bpf". */ const char *pin_root_path; __u32 :32; /* stub out now removed attach_prog_fd */ /* Additional kernel config content that augments and overrides * system Kconfig for CONFIG_xxx externs. */ const char *kconfig; /* Path to the custom BTF to be used for BPF CO-RE relocations. * This custom BTF completely replaces the use of vmlinux BTF * for the purpose of CO-RE relocations. * NOTE: any other BPF feature (e.g., fentry/fexit programs, * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux. */ const char *btf_custom_path; /* Pointer to a buffer for storing kernel logs for applicable BPF * commands. Valid kernel_log_size has to be specified as well and are * passed-through to bpf() syscall. Keep in mind that kernel might * fail operation with -ENOSPC error if provided buffer is too small * to contain entire log output. * See the comment below for kernel_log_level for interaction between * log_buf and log_level settings. * * If specified, this log buffer will be passed for: * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overridden * with bpf_program__set_log() on per-program level, to get * BPF verifier log output. * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get * BTF sanity checking log. * * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite * previous contents, so if you need more fine-grained control, set * per-program buffer with bpf_program__set_log_buf() to preserve each * individual program's verification log. Keep using kernel_log_buf * for BTF verification log, if necessary. */ char *kernel_log_buf; size_t kernel_log_size; /* * Log level can be set independently from log buffer. Log_level=0 * means that libbpf will attempt loading BTF or program without any * logging requested, but will retry with either its own or custom log * buffer, if provided, and log_level=1 on any error. * And vice versa, setting log_level>0 will request BTF or prog * loading with verbose log from the first attempt (and as such also * for successfully loaded BTF or program), and the actual log buffer * could be either libbpf's own auto-allocated log buffer, if * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf. * If user didn't provide custom log buffer, libbpf will emit captured * logs through its print callback. */ __u32 kernel_log_level; /* Path to BPF FS mount point to derive BPF token from. * * Created BPF token will be used for all bpf() syscall operations * that accept BPF token (e.g., map creation, BTF and program loads, * etc) automatically within instantiated BPF object. * * If bpf_token_path is not specified, libbpf will consult * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be * taken as a value of bpf_token_path option and will force libbpf to * either create BPF token from provided custom BPF FS path, or will * disable implicit BPF token creation, if envvar value is an empty * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are * set at the same time. * * Setting bpf_token_path option to empty string disables libbpf's * automatic attempt to create BPF token from default BPF FS mount * point (/sys/fs/bpf), in case this default behavior is undesirable. */ const char *bpf_token_path; size_t :0; }; #define bpf_object_open_opts__last_field bpf_token_path /** * @brief **bpf_object__open()** creates a bpf_object by opening * the BPF ELF object file pointed to by the passed path and loading it * into memory. * @param path BPF object file path. * @return pointer to the new bpf_object; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_object *bpf_object__open(const char *path); /** * @brief **bpf_object__open_file()** creates a bpf_object by opening * the BPF ELF object file pointed to by the passed path and loading it * into memory. * @param path BPF object file path * @param opts options for how to load the bpf object, this parameter is * optional and can be set to NULL * @return pointer to the new bpf_object; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_object * bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts); /** * @brief **bpf_object__open_mem()** creates a bpf_object by reading * the BPF objects raw bytes from a memory buffer containing a valid * BPF ELF object file. * @param obj_buf pointer to the buffer containing ELF file bytes * @param obj_buf_sz number of bytes in the buffer * @param opts options for how to load the bpf object * @return pointer to the new bpf_object; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_object * bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, const struct bpf_object_open_opts *opts); /** * @brief **bpf_object__load()** loads BPF object into kernel. * @param obj Pointer to a valid BPF object instance returned by * **bpf_object__open*()** APIs * @return 0, on success; negative error code, otherwise, error code is * stored in errno */ LIBBPF_API int bpf_object__load(struct bpf_object *obj); /** * @brief **bpf_object__close()** closes a BPF object and releases all * resources. * @param obj Pointer to a valid BPF object */ LIBBPF_API void bpf_object__close(struct bpf_object *obj); /** * @brief **bpf_object__pin_maps()** pins each map contained within * the BPF object at the passed directory. * @param obj Pointer to a valid BPF object * @param path A directory where maps should be pinned. * @return 0, on success; negative error code, otherwise * * If `path` is NULL `bpf_map__pin` (which is being used on each map) * will use the pin_path attribute of each map. In this case, maps that * don't have a pin_path set will be ignored. */ LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path); /** * @brief **bpf_object__unpin_maps()** unpins each map contained within * the BPF object found in the passed directory. * @param obj Pointer to a valid BPF object * @param path A directory where pinned maps should be searched for. * @return 0, on success; negative error code, otherwise * * If `path` is NULL `bpf_map__unpin` (which is being used on each map) * will use the pin_path attribute of each map. In this case, maps that * don't have a pin_path set will be ignored. */ LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj, const char *path); LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj, const char *path); LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj, const char *path); LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); LIBBPF_API int bpf_object__unpin(struct bpf_object *object, const char *path); LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version); /** * @brief **bpf_object__token_fd** is an accessor for BPF token FD associated * with BPF object. * @param obj Pointer to a valid BPF object * @return BPF token FD or -1, if it wasn't set */ LIBBPF_API int bpf_object__token_fd(const struct bpf_object *obj); struct btf; LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); LIBBPF_API struct bpf_program * bpf_object__find_program_by_name(const struct bpf_object *obj, const char *name); LIBBPF_API int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, enum bpf_attach_type *expected_attach_type); LIBBPF_API int libbpf_attach_type_by_name(const char *name, enum bpf_attach_type *attach_type); LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name, enum bpf_attach_type attach_type); /* Accessors of bpf_program */ struct bpf_program; LIBBPF_API struct bpf_program * bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog); #define bpf_object__for_each_program(pos, obj) \ for ((pos) = bpf_object__next_program((obj), NULL); \ (pos) != NULL; \ (pos) = bpf_object__next_program((obj), (pos))) LIBBPF_API struct bpf_program * bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog); LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex); LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog); LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog); LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog); LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload); LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog); LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach); struct bpf_insn; /** * @brief **bpf_program__insns()** gives read-only access to BPF program's * underlying BPF instructions. * @param prog BPF program for which to return instructions * @return a pointer to an array of BPF instructions that belong to the * specified BPF program * * Returned pointer is always valid and not NULL. Number of `struct bpf_insn` * pointed to can be fetched using **bpf_program__insn_cnt()** API. * * Keep in mind, libbpf can modify and append/delete BPF program's * instructions as it processes BPF object file and prepares everything for * uploading into the kernel. So depending on the point in BPF object * lifetime, **bpf_program__insns()** can return different sets of * instructions. As an example, during BPF object load phase BPF program * instructions will be CO-RE-relocated, BPF subprograms instructions will be * appended, ldimm64 instructions will have FDs embedded, etc. So instructions * returned before **bpf_object__load()** and after it might be quite * different. */ LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog); /** * @brief **bpf_program__set_insns()** can set BPF program's underlying * BPF instructions. * * WARNING: This is a very advanced libbpf API and users need to know * what they are doing. This should be used from prog_prepare_load_fn * callback only. * * @param prog BPF program for which to return instructions * @param new_insns a pointer to an array of BPF instructions * @param new_insn_cnt number of `struct bpf_insn`'s that form * specified BPF program * @return 0, on success; negative error code, otherwise */ LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog, struct bpf_insn *new_insns, size_t new_insn_cnt); /** * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s * that form specified BPF program. * @param prog BPF program for which to return number of BPF instructions * * See **bpf_program__insns()** documentation for notes on how libbpf can * change instructions and their count during different phases of * **bpf_object** lifetime. */ LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog); LIBBPF_API int bpf_program__fd(const struct bpf_program *prog); /** * @brief **bpf_program__pin()** pins the BPF program to a file * in the BPF FS specified by a path. This increments the programs * reference count, allowing it to stay loaded after the process * which loaded it has exited. * * @param prog BPF program to pin, must already be loaded * @param path file path in a BPF file system * @return 0, on success; negative error code, otherwise */ LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); /** * @brief **bpf_program__unpin()** unpins the BPF program from a file * in the BPFFS specified by a path. This decrements the programs * reference count. * * The file pinning the BPF program can also be unlinked by a different * process in which case this function will return an error. * * @param prog BPF program to unpin * @param path file path to the pin in a BPF file system * @return 0, on success; negative error code, otherwise */ LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path); LIBBPF_API void bpf_program__unload(struct bpf_program *prog); struct bpf_link; LIBBPF_API struct bpf_link *bpf_link__open(const char *path); LIBBPF_API int bpf_link__fd(const struct bpf_link *link); LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link); /** * @brief **bpf_link__pin()** pins the BPF link to a file * in the BPF FS specified by a path. This increments the links * reference count, allowing it to stay loaded after the process * which loaded it has exited. * * @param link BPF link to pin, must already be loaded * @param path file path in a BPF file system * @return 0, on success; negative error code, otherwise */ LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path); /** * @brief **bpf_link__unpin()** unpins the BPF link from a file * in the BPFFS specified by a path. This decrements the links * reference count. * * The file pinning the BPF link can also be unlinked by a different * process in which case this function will return an error. * * @param prog BPF program to unpin * @param path file path to the pin in a BPF file system * @return 0, on success; negative error code, otherwise */ LIBBPF_API int bpf_link__unpin(struct bpf_link *link); LIBBPF_API int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog); LIBBPF_API void bpf_link__disconnect(struct bpf_link *link); LIBBPF_API int bpf_link__detach(struct bpf_link *link); LIBBPF_API int bpf_link__destroy(struct bpf_link *link); /** * @brief **bpf_program__attach()** is a generic function for attaching * a BPF program based on auto-detection of program type, attach type, * and extra parameters, where applicable. * * @param prog BPF program to attach * @return Reference to the newly created BPF link; or NULL is returned on error, * error code is stored in errno * * This is supported for: * - kprobe/kretprobe (depends on SEC() definition) * - uprobe/uretprobe (depends on SEC() definition) * - tracepoint * - raw tracepoint * - tracing programs (typed raw TP/fentry/fexit/fmod_ret) */ LIBBPF_API struct bpf_link * bpf_program__attach(const struct bpf_program *prog); struct bpf_perf_event_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; /* don't use BPF link when attach BPF program */ bool force_ioctl_attach; size_t :0; }; #define bpf_perf_event_opts__last_field force_ioctl_attach LIBBPF_API struct bpf_link * bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); LIBBPF_API struct bpf_link * bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, const struct bpf_perf_event_opts *opts); /** * enum probe_attach_mode - the mode to attach kprobe/uprobe * * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will * be returned if it is not supported by the kernel. */ enum probe_attach_mode { /* attach probe in latest supported mode by kernel */ PROBE_ATTACH_MODE_DEFAULT = 0, /* attach probe in legacy mode, using debugfs/tracefs */ PROBE_ATTACH_MODE_LEGACY, /* create perf event with perf_event_open() syscall */ PROBE_ATTACH_MODE_PERF, /* attach probe with BPF link */ PROBE_ATTACH_MODE_LINK, }; struct bpf_kprobe_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; /* function's offset to install kprobe to */ size_t offset; /* kprobe is return probe */ bool retprobe; /* kprobe attach mode */ enum probe_attach_mode attach_mode; size_t :0; }; #define bpf_kprobe_opts__last_field attach_mode LIBBPF_API struct bpf_link * bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, const char *func_name); LIBBPF_API struct bpf_link * bpf_program__attach_kprobe_opts(const struct bpf_program *prog, const char *func_name, const struct bpf_kprobe_opts *opts); struct bpf_kprobe_multi_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* array of function symbols to attach */ const char **syms; /* array of function addresses to attach */ const unsigned long *addrs; /* array of user-provided values fetchable through bpf_get_attach_cookie */ const __u64 *cookies; /* number of elements in syms/addrs/cookies arrays */ size_t cnt; /* create return kprobes */ bool retprobe; /* create session kprobes */ bool session; size_t :0; }; #define bpf_kprobe_multi_opts__last_field session LIBBPF_API struct bpf_link * bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, const char *pattern, const struct bpf_kprobe_multi_opts *opts); struct bpf_uprobe_multi_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* array of function symbols to attach to */ const char **syms; /* array of function addresses to attach to */ const unsigned long *offsets; /* optional, array of associated ref counter offsets */ const unsigned long *ref_ctr_offsets; /* optional, array of associated BPF cookies */ const __u64 *cookies; /* number of elements in syms/addrs/cookies arrays */ size_t cnt; /* create return uprobes */ bool retprobe; /* create session kprobes */ bool session; size_t :0; }; #define bpf_uprobe_multi_opts__last_field session /** * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program * to multiple uprobes with uprobe_multi link. * * User can specify 2 mutually exclusive set of inputs: * * 1) use only path/func_pattern/pid arguments * * 2) use path/pid with allowed combinations of * syms/offsets/ref_ctr_offsets/cookies/cnt * * - syms and offsets are mutually exclusive * - ref_ctr_offsets and cookies are optional * * * @param prog BPF program to attach * @param pid Process ID to attach the uprobe to, 0 for self (own process), * -1 for all processes * @param binary_path Path to binary * @param func_pattern Regular expression to specify functions to attach * BPF program to * @param opts Additional options (see **struct bpf_uprobe_multi_opts**) * @return 0, on success; negative error code, otherwise */ LIBBPF_API struct bpf_link * bpf_program__attach_uprobe_multi(const struct bpf_program *prog, pid_t pid, const char *binary_path, const char *func_pattern, const struct bpf_uprobe_multi_opts *opts); struct bpf_ksyscall_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; /* attach as return probe? */ bool retprobe; size_t :0; }; #define bpf_ksyscall_opts__last_field retprobe /** * @brief **bpf_program__attach_ksyscall()** attaches a BPF program * to kernel syscall handler of a specified syscall. Optionally it's possible * to request to install retprobe that will be triggered at syscall exit. It's * also possible to associate BPF cookie (though options). * * Libbpf automatically will determine correct full kernel function name, * which depending on system architecture and kernel version/configuration * could be of the form ___sys_ or __se_sys_, and will * attach specified program using kprobe/kretprobe mechanism. * * **bpf_program__attach_ksyscall()** is an API counterpart of declarative * **SEC("ksyscall/")** annotation of BPF programs. * * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do * not handle all the calling convention quirks for mmap(), clone() and compat * syscalls. It also only attaches to "native" syscall interfaces. If host * system supports compat syscalls or defines 32-bit syscalls in 64-bit * kernel, such syscall interfaces won't be attached to by libbpf. * * These limitations may or may not change in the future. Therefore it is * recommended to use SEC("kprobe") for these syscalls or if working with * compat and 32-bit interfaces is required. * * @param prog BPF program to attach * @param syscall_name Symbolic name of the syscall (e.g., "bpf") * @param opts Additional options (see **struct bpf_ksyscall_opts**) * @return Reference to the newly created BPF link; or NULL is returned on * error, error code is stored in errno */ LIBBPF_API struct bpf_link * bpf_program__attach_ksyscall(const struct bpf_program *prog, const char *syscall_name, const struct bpf_ksyscall_opts *opts); struct bpf_uprobe_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* offset of kernel reference counted USDT semaphore, added in * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe") */ size_t ref_ctr_offset; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; /* uprobe is return probe, invoked at function return time */ bool retprobe; /* Function name to attach to. Could be an unqualified ("abc") or library-qualified * "abc@LIBXYZ" name. To specify function entry, func_name should be set while * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an * offset within a function, specify func_name and use func_offset argument to specify * offset within the function. Shared library functions must specify the shared library * binary_path. */ const char *func_name; /* uprobe attach mode */ enum probe_attach_mode attach_mode; size_t :0; }; #define bpf_uprobe_opts__last_field attach_mode /** * @brief **bpf_program__attach_uprobe()** attaches a BPF program * to the userspace function which is found by binary path and * offset. You can optionally specify a particular process to attach * to. You can also optionally attach the program to the function * exit instead of entry. * * @param prog BPF program to attach * @param retprobe Attach to function exit * @param pid Process ID to attach the uprobe to, 0 for self (own process), * -1 for all processes * @param binary_path Path to binary that contains the function symbol * @param func_offset Offset within the binary of the function symbol * @return Reference to the newly created BPF link; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_link * bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe, pid_t pid, const char *binary_path, size_t func_offset); /** * @brief **bpf_program__attach_uprobe_opts()** is just like * bpf_program__attach_uprobe() except with a options struct * for various configurations. * * @param prog BPF program to attach * @param pid Process ID to attach the uprobe to, 0 for self (own process), * -1 for all processes * @param binary_path Path to binary that contains the function symbol * @param func_offset Offset within the binary of the function symbol * @param opts Options for altering program attachment * @return Reference to the newly created BPF link; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_link * bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, const char *binary_path, size_t func_offset, const struct bpf_uprobe_opts *opts); struct bpf_usdt_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value accessible through usdt_cookie() */ __u64 usdt_cookie; size_t :0; }; #define bpf_usdt_opts__last_field usdt_cookie /** * @brief **bpf_program__attach_usdt()** is just like * bpf_program__attach_uprobe_opts() except it covers USDT (User-space * Statically Defined Tracepoint) attachment, instead of attaching to * user-space function entry or exit. * * @param prog BPF program to attach * @param pid Process ID to attach the uprobe to, 0 for self (own process), * -1 for all processes * @param binary_path Path to binary that contains provided USDT probe * @param usdt_provider USDT provider name * @param usdt_name USDT probe name * @param opts Options for altering program attachment * @return Reference to the newly created BPF link; or NULL is returned on error, * error code is stored in errno */ LIBBPF_API struct bpf_link * bpf_program__attach_usdt(const struct bpf_program *prog, pid_t pid, const char *binary_path, const char *usdt_provider, const char *usdt_name, const struct bpf_usdt_opts *opts); struct bpf_tracepoint_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; }; #define bpf_tracepoint_opts__last_field bpf_cookie LIBBPF_API struct bpf_link * bpf_program__attach_tracepoint(const struct bpf_program *prog, const char *tp_category, const char *tp_name); LIBBPF_API struct bpf_link * bpf_program__attach_tracepoint_opts(const struct bpf_program *prog, const char *tp_category, const char *tp_name, const struct bpf_tracepoint_opts *opts); struct bpf_raw_tracepoint_opts { size_t sz; /* size of this struct for forward/backward compatibility */ __u64 cookie; size_t :0; }; #define bpf_raw_tracepoint_opts__last_field cookie LIBBPF_API struct bpf_link * bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, const char *tp_name); LIBBPF_API struct bpf_link * bpf_program__attach_raw_tracepoint_opts(const struct bpf_program *prog, const char *tp_name, struct bpf_raw_tracepoint_opts *opts); struct bpf_trace_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 cookie; }; #define bpf_trace_opts__last_field cookie LIBBPF_API struct bpf_link * bpf_program__attach_trace(const struct bpf_program *prog); LIBBPF_API struct bpf_link * bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts); LIBBPF_API struct bpf_link * bpf_program__attach_lsm(const struct bpf_program *prog); LIBBPF_API struct bpf_link * bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); LIBBPF_API struct bpf_link * bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd); LIBBPF_API struct bpf_link * bpf_program__attach_sockmap(const struct bpf_program *prog, int map_fd); LIBBPF_API struct bpf_link * bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex); LIBBPF_API struct bpf_link * bpf_program__attach_freplace(const struct bpf_program *prog, int target_fd, const char *attach_func_name); struct bpf_netfilter_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; __u32 pf; __u32 hooknum; __s32 priority; __u32 flags; }; #define bpf_netfilter_opts__last_field flags LIBBPF_API struct bpf_link * bpf_program__attach_netfilter(const struct bpf_program *prog, const struct bpf_netfilter_opts *opts); struct bpf_tcx_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; __u32 flags; __u32 relative_fd; __u32 relative_id; __u64 expected_revision; size_t :0; }; #define bpf_tcx_opts__last_field expected_revision LIBBPF_API struct bpf_link * bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex, const struct bpf_tcx_opts *opts); struct bpf_netkit_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; __u32 flags; __u32 relative_fd; __u32 relative_id; __u64 expected_revision; size_t :0; }; #define bpf_netkit_opts__last_field expected_revision LIBBPF_API struct bpf_link * bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex, const struct bpf_netkit_opts *opts); struct bpf_map; LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map); LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map); struct bpf_iter_attach_opts { size_t sz; /* size of this struct for forward/backward compatibility */ union bpf_iter_link_info *link_info; __u32 link_info_len; }; #define bpf_iter_attach_opts__last_field link_info_len LIBBPF_API struct bpf_link * bpf_program__attach_iter(const struct bpf_program *prog, const struct bpf_iter_attach_opts *opts); LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog); /** * @brief **bpf_program__set_type()** sets the program * type of the passed BPF program. * @param prog BPF program to set the program type for * @param type program type to set the BPF map to have * @return error code; or 0 if no error. An error occurs * if the object is already loaded. * * This must be called before the BPF object is loaded, * otherwise it has no effect and an error is returned. */ LIBBPF_API int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type); LIBBPF_API enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog); /** * @brief **bpf_program__set_expected_attach_type()** sets the * attach type of the passed BPF program. This is used for * auto-detection of attachment when programs are loaded. * @param prog BPF program to set the attach type for * @param type attach type to set the BPF map to have * @return error code; or 0 if no error. An error occurs * if the object is already loaded. * * This must be called before the BPF object is loaded, * otherwise it has no effect and an error is returned. */ LIBBPF_API int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type); LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog); LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags); /* Per-program log level and log buffer getters/setters. * See bpf_object_open_opts comments regarding log_level and log_buf * interactions. */ LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog); LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level); LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size); LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size); /** * @brief **bpf_program__set_attach_target()** sets BTF-based attach target * for supported BPF program types: * - BTF-aware raw tracepoints (tp_btf); * - fentry/fexit/fmod_ret; * - lsm; * - freplace. * @param prog BPF program to set the attach type for * @param type attach type to set the BPF map to have * @return error code; or 0 if no error occurred. */ LIBBPF_API int bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, const char *attach_func_name); /** * @brief **bpf_object__find_map_by_name()** returns BPF map of * the given name, if it exists within the passed BPF object * @param obj BPF object * @param name name of the BPF map * @return BPF map instance, if such map exists within the BPF object; * or NULL otherwise. */ LIBBPF_API struct bpf_map * bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name); LIBBPF_API int bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name); LIBBPF_API struct bpf_map * bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map); #define bpf_object__for_each_map(pos, obj) \ for ((pos) = bpf_object__next_map((obj), NULL); \ (pos) != NULL; \ (pos) = bpf_object__next_map((obj), (pos))) #define bpf_map__for_each bpf_object__for_each_map LIBBPF_API struct bpf_map * bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map); /** * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create * BPF map during BPF object load phase. * @param map the BPF map instance * @param autocreate whether to create BPF map during BPF object load * @return 0 on success; -EBUSY if BPF object was already loaded * * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating * BPF map. By default, libbpf will attempt to create every single BPF map * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall * and fill in map FD in BPF instructions. * * This API allows to opt-out of this process for specific map instance. This * can be useful if host kernel doesn't support such BPF map type or used * combination of flags and user application wants to avoid creating such * a map in the first place. User is still responsible to make sure that their * BPF-side code that expects to use such missing BPF map is recognized by BPF * verifier as dead code, otherwise BPF verifier will reject such BPF program. */ LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate); LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map); /** * @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach * map during BPF skeleton attach phase. * @param map the BPF map instance * @param autoattach whether to attach map during BPF skeleton attach phase * @return 0 on success; negative error code, otherwise */ LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach); /** * @brief **bpf_map__autoattach()** returns whether BPF map is configured to * auto-attach during BPF skeleton attach phase. * @param map the BPF map instance * @return true if map is set to auto-attach during skeleton attach phase; false, otherwise */ LIBBPF_API bool bpf_map__autoattach(const struct bpf_map *map); /** * @brief **bpf_map__fd()** gets the file descriptor of the passed * BPF map * @param map the BPF map instance * @return the file descriptor; or -EINVAL in case of an error */ LIBBPF_API int bpf_map__fd(const struct bpf_map *map); LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); /* get map name */ LIBBPF_API const char *bpf_map__name(const struct bpf_map *map); /* get/set map type */ LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map); LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type); /* get/set map size (max_entries) */ LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map); LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries); /* get/set map flags */ LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map); LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags); /* get/set map NUMA node */ LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map); LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node); /* get/set map key size */ LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map); LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size); /* get map value size */ LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map); /** * @brief **bpf_map__set_value_size()** sets map value size. * @param map the BPF map instance * @return 0, on success; negative error, otherwise * * There is a special case for maps with associated memory-mapped regions, like * the global data section maps (bss, data, rodata). When this function is used * on such a map, the mapped region is resized. Afterward, an attempt is made to * adjust the corresponding BTF info. This attempt is best-effort and can only * succeed if the last variable of the data section map is an array. The array * BTF type is replaced by a new BTF array type with a different length. * Any previously existing pointers returned from bpf_map__initial_value() or * corresponding data section skeleton pointer must be reinitialized. */ LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size); /* get map key/value BTF type IDs */ LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); /* get/set map if_index */ LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map); LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); /* get/set map map_extra flags */ LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map); LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra); LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map, const void *data, size_t size); LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize); /** * @brief **bpf_map__is_internal()** tells the caller whether or not the * passed map is a special map created by libbpf automatically for things like * global variables, __ksym externs, Kconfig values, etc * @param map the bpf_map * @return true, if the map is an internal map; false, otherwise */ LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map); /** * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the * BPF map should be pinned. This does not actually create the 'pin'. * @param map The bpf_map * @param path The path * @return 0, on success; negative error, otherwise */ LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path); /** * @brief **bpf_map__pin_path()** gets the path attribute that tells where the * BPF map should be pinned. * @param map The bpf_map * @return The path string; which can be NULL */ LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map); /** * @brief **bpf_map__is_pinned()** tells the caller whether or not the * passed map has been pinned via a 'pin' file. * @param map The bpf_map * @return true, if the map is pinned; false, otherwise */ LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map); /** * @brief **bpf_map__pin()** creates a file that serves as a 'pin' * for the BPF map. This increments the reference count on the * BPF map which will keep the BPF map loaded even after the * userspace process which loaded it has exited. * @param map The bpf_map to pin * @param path A file path for the 'pin' * @return 0, on success; negative error, otherwise * * If `path` is NULL the maps `pin_path` attribute will be used. If this is * also NULL, an error will be returned and the map will not be pinned. */ LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); /** * @brief **bpf_map__unpin()** removes the file that serves as a * 'pin' for the BPF map. * @param map The bpf_map to unpin * @param path A file path for the 'pin' * @return 0, on success; negative error, otherwise * * The `path` parameter can be NULL, in which case the `pin_path` * map attribute is unpinned. If both the `path` parameter and * `pin_path` map attribute are set, they must be equal. */ LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path); LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd); LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map); /** * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value * corresponding to provided key. * @param map BPF map to lookup element in * @param key pointer to memory containing bytes of the key used for lookup * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** * @param value pointer to memory in which looked up value will be stored * @param value_sz size in byte of value data memory; it has to match BPF map * definition's **value_size**. For per-CPU BPF maps value size has to be * a product of BPF map value size and number of possible CPUs in the system * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for * per-CPU values value size has to be aligned up to closest 8 bytes for * alignment reasons, so expected size is: `round_up(value_size, 8) * * libbpf_num_possible_cpus()`. * @flags extra flags passed to kernel for this operation * @return 0, on success; negative error, otherwise * * **bpf_map__lookup_elem()** is high-level equivalent of * **bpf_map_lookup_elem()** API with added check for key and value size. */ LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map, const void *key, size_t key_sz, void *value, size_t value_sz, __u64 flags); /** * @brief **bpf_map__update_elem()** allows to insert or update value in BPF * map that corresponds to provided key. * @param map BPF map to insert to or update element in * @param key pointer to memory containing bytes of the key * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** * @param value pointer to memory containing bytes of the value * @param value_sz size in byte of value data memory; it has to match BPF map * definition's **value_size**. For per-CPU BPF maps value size has to be * a product of BPF map value size and number of possible CPUs in the system * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for * per-CPU values value size has to be aligned up to closest 8 bytes for * alignment reasons, so expected size is: `round_up(value_size, 8) * * libbpf_num_possible_cpus()`. * @flags extra flags passed to kernel for this operation * @return 0, on success; negative error, otherwise * * **bpf_map__update_elem()** is high-level equivalent of * **bpf_map_update_elem()** API with added check for key and value size. */ LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map, const void *key, size_t key_sz, const void *value, size_t value_sz, __u64 flags); /** * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that * corresponds to provided key. * @param map BPF map to delete element from * @param key pointer to memory containing bytes of the key * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** * @flags extra flags passed to kernel for this operation * @return 0, on success; negative error, otherwise * * **bpf_map__delete_elem()** is high-level equivalent of * **bpf_map_delete_elem()** API with added check for key size. */ LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map, const void *key, size_t key_sz, __u64 flags); /** * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value * corresponding to provided key and atomically delete it afterwards. * @param map BPF map to lookup element in * @param key pointer to memory containing bytes of the key used for lookup * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** * @param value pointer to memory in which looked up value will be stored * @param value_sz size in byte of value data memory; it has to match BPF map * definition's **value_size**. For per-CPU BPF maps value size has to be * a product of BPF map value size and number of possible CPUs in the system * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for * per-CPU values value size has to be aligned up to closest 8 bytes for * alignment reasons, so expected size is: `round_up(value_size, 8) * * libbpf_num_possible_cpus()`. * @flags extra flags passed to kernel for this operation * @return 0, on success; negative error, otherwise * * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size. */ LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, const void *key, size_t key_sz, void *value, size_t value_sz, __u64 flags); /** * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by * fetching next key that follows current key. * @param map BPF map to fetch next key from * @param cur_key pointer to memory containing bytes of current key or NULL to * fetch the first key * @param next_key pointer to memory to write next key into * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size** * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map; * negative error, otherwise * * **bpf_map__get_next_key()** is high-level equivalent of * **bpf_map_get_next_key()** API with added check for key size. */ LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, const void *cur_key, void *next_key, size_t key_sz); struct bpf_xdp_set_link_opts { size_t sz; int old_fd; size_t :0; }; #define bpf_xdp_set_link_opts__last_field old_fd struct bpf_xdp_attach_opts { size_t sz; int old_prog_fd; size_t :0; }; #define bpf_xdp_attach_opts__last_field old_prog_fd struct bpf_xdp_query_opts { size_t sz; __u32 prog_id; /* output */ __u32 drv_prog_id; /* output */ __u32 hw_prog_id; /* output */ __u32 skb_prog_id; /* output */ __u8 attach_mode; /* output */ __u64 feature_flags; /* output */ __u32 xdp_zc_max_segs; /* output */ size_t :0; }; #define bpf_xdp_query_opts__last_field xdp_zc_max_segs LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags, const struct bpf_xdp_attach_opts *opts); LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags, const struct bpf_xdp_attach_opts *opts); LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts); LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id); /* TC related API */ enum bpf_tc_attach_point { BPF_TC_INGRESS = 1 << 0, BPF_TC_EGRESS = 1 << 1, BPF_TC_CUSTOM = 1 << 2, }; #define BPF_TC_PARENT(a, b) \ ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU)) enum bpf_tc_flags { BPF_TC_F_REPLACE = 1 << 0, }; struct bpf_tc_hook { size_t sz; int ifindex; enum bpf_tc_attach_point attach_point; __u32 parent; size_t :0; }; #define bpf_tc_hook__last_field parent struct bpf_tc_opts { size_t sz; int prog_fd; __u32 flags; __u32 prog_id; __u32 handle; __u32 priority; size_t :0; }; #define bpf_tc_opts__last_field priority LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook); LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook); LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts); LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook, const struct bpf_tc_opts *opts); LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook, struct bpf_tc_opts *opts); /* Ring buffer APIs */ struct ring_buffer; struct ring; struct user_ring_buffer; typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size); struct ring_buffer_opts { size_t sz; /* size of this struct, for forward/backward compatibility */ }; #define ring_buffer_opts__last_field sz LIBBPF_API struct ring_buffer * ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx, const struct ring_buffer_opts *opts); LIBBPF_API void ring_buffer__free(struct ring_buffer *rb); LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd, ring_buffer_sample_fn sample_cb, void *ctx); LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms); LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb); LIBBPF_API int ring_buffer__consume_n(struct ring_buffer *rb, size_t n); LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb); /** * @brief **ring_buffer__ring()** returns the ringbuffer object inside a given * ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance. * * @param rb A ringbuffer manager object. * @param idx An index into the ringbuffers contained within the ringbuffer * manager object. The index is 0-based and corresponds to the order in which * ring_buffer__add was called. * @return A ringbuffer object on success; NULL and errno set if the index is * invalid. */ LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb, unsigned int idx); /** * @brief **ring__consumer_pos()** returns the current consumer position in the * given ringbuffer. * * @param r A ringbuffer object. * @return The current consumer position. */ LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r); /** * @brief **ring__producer_pos()** returns the current producer position in the * given ringbuffer. * * @param r A ringbuffer object. * @return The current producer position. */ LIBBPF_API unsigned long ring__producer_pos(const struct ring *r); /** * @brief **ring__avail_data_size()** returns the number of bytes in the * ringbuffer not yet consumed. This has no locking associated with it, so it * can be inaccurate if operations are ongoing while this is called. However, it * should still show the correct trend over the long-term. * * @param r A ringbuffer object. * @return The number of bytes not yet consumed. */ LIBBPF_API size_t ring__avail_data_size(const struct ring *r); /** * @brief **ring__size()** returns the total size of the ringbuffer's map data * area (excluding special producer/consumer pages). Effectively this gives the * amount of usable bytes of data inside the ringbuffer. * * @param r A ringbuffer object. * @return The total size of the ringbuffer map data area. */ LIBBPF_API size_t ring__size(const struct ring *r); /** * @brief **ring__map_fd()** returns the file descriptor underlying the given * ringbuffer. * * @param r A ringbuffer object. * @return The underlying ringbuffer file descriptor */ LIBBPF_API int ring__map_fd(const struct ring *r); /** * @brief **ring__consume()** consumes available ringbuffer data without event * polling. * * @param r A ringbuffer object. * @return The number of records consumed (or INT_MAX, whichever is less), or * a negative number if any of the callbacks return an error. */ LIBBPF_API int ring__consume(struct ring *r); /** * @brief **ring__consume_n()** consumes up to a requested amount of items from * a ringbuffer without event polling. * * @param r A ringbuffer object. * @param n Maximum amount of items to consume. * @return The number of items consumed, or a negative number if any of the * callbacks return an error. */ LIBBPF_API int ring__consume_n(struct ring *r, size_t n); struct user_ring_buffer_opts { size_t sz; /* size of this struct, for forward/backward compatibility */ }; #define user_ring_buffer_opts__last_field sz /** * @brief **user_ring_buffer__new()** creates a new instance of a user ring * buffer. * * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map. * @param opts Options for how the ring buffer should be created. * @return A user ring buffer on success; NULL and errno being set on a * failure. */ LIBBPF_API struct user_ring_buffer * user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); /** * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the * user ring buffer. * @param rb A pointer to a user ring buffer. * @param size The size of the sample, in bytes. * @return A pointer to an 8-byte aligned reserved region of the user ring * buffer; NULL, and errno being set if a sample could not be reserved. * * This function is *not* thread safe, and callers must synchronize accessing * this function if there are multiple producers. If a size is requested that * is larger than the size of the entire ring buffer, errno will be set to * E2BIG and NULL is returned. If the ring buffer could accommodate the size, * but currently does not have enough space, errno is set to ENOSPC and NULL is * returned. * * After initializing the sample, callers must invoke * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise, * the sample must be freed with **user_ring_buffer__discard()**. */ LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); /** * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes * available. * @param rb The user ring buffer. * @param size The size of the sample, in bytes. * @param timeout_ms The amount of time, in milliseconds, for which the caller * should block when waiting for a sample. -1 causes the caller to block * indefinitely. * @return A pointer to an 8-byte aligned reserved region of the user ring * buffer; NULL, and errno being set if a sample could not be reserved. * * This function is *not* thread safe, and callers must synchronize * accessing this function if there are multiple producers * * If **timeout_ms** is -1, the function will block indefinitely until a sample * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking * will occur and the function will return immediately after attempting to * reserve a sample. * * If **size** is larger than the size of the entire ring buffer, errno is set * to E2BIG and NULL is returned. If the ring buffer could accommodate * **size**, but currently does not have enough space, the caller will block * until at most **timeout_ms** has elapsed. If insufficient space is available * at that time, errno is set to ENOSPC, and NULL is returned. * * The kernel guarantees that it will wake up this thread to check if * sufficient space is available in the ring buffer at least once per * invocation of the **bpf_ringbuf_drain()** helper function, provided that at * least one sample is consumed, and the BPF program did not invoke the * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the * kernel does not guarantee this. If the helper function is invoked with * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is * consumed. * * When a sample of size **size** is found within **timeout_ms**, a pointer to * the sample is returned. After initializing the sample, callers must invoke * **user_ring_buffer__submit()** to post the sample to the ring buffer. * Otherwise, the sample must be freed with **user_ring_buffer__discard()**. */ LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, __u32 size, int timeout_ms); /** * @brief **user_ring_buffer__submit()** submits a previously reserved sample * into the ring buffer. * @param rb The user ring buffer. * @param sample A reserved sample. * * It is not necessary to synchronize amongst multiple producers when invoking * this function. */ LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); /** * @brief **user_ring_buffer__discard()** discards a previously reserved sample. * @param rb The user ring buffer. * @param sample A reserved sample. * * It is not necessary to synchronize amongst multiple producers when invoking * this function. */ LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample); /** * @brief **user_ring_buffer__free()** frees a ring buffer that was previously * created with **user_ring_buffer__new()**. * @param rb The user ring buffer being freed. */ LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb); /* Perf buffer APIs */ struct perf_buffer; typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu, void *data, __u32 size); typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt); /* common use perf buffer options */ struct perf_buffer_opts { size_t sz; __u32 sample_period; size_t :0; }; #define perf_buffer_opts__last_field sample_period /** * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified * BPF_PERF_EVENT_ARRAY map * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF * code to send data over to user-space * @param page_cnt number of memory pages allocated for each per-CPU buffer * @param sample_cb function called on each received data record * @param lost_cb function called when record loss has occurred * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb* * @return a new instance of struct perf_buffer on success, NULL on error with * *errno* containing an error code */ LIBBPF_API struct perf_buffer * perf_buffer__new(int map_fd, size_t page_cnt, perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx, const struct perf_buffer_opts *opts); enum bpf_perf_event_ret { LIBBPF_PERF_EVENT_DONE = 0, LIBBPF_PERF_EVENT_ERROR = -1, LIBBPF_PERF_EVENT_CONT = -2, }; struct perf_event_header; typedef enum bpf_perf_event_ret (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event); /* raw perf buffer options, giving most power and control */ struct perf_buffer_raw_opts { size_t sz; long :0; long :0; /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of * max_entries of given PERF_EVENT_ARRAY map) */ int cpu_cnt; /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */ int *cpus; /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */ int *map_keys; }; #define perf_buffer_raw_opts__last_field map_keys struct perf_event_attr; LIBBPF_API struct perf_buffer * perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr, perf_buffer_event_fn event_cb, void *ctx, const struct perf_buffer_raw_opts *opts); LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb); LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); /** * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying * memory region of the ring buffer. * This ring buffer can be used to implement a custom events consumer. * The ring buffer starts with the *struct perf_event_mmap_page*, which * holds the ring buffer management fields, when accessing the header * structure it's important to be SMP aware. * You can refer to *perf_event_read_simple* for a simple example. * @param pb the perf buffer structure * @param buf_idx the buffer index to retrieve * @param buf (out) gets the base pointer of the mmap()'ed memory * @param buf_size (out) gets the size of the mmap()'ed region * @return 0 on success, negative error code for failure */ LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, size_t *buf_size); struct bpf_prog_linfo; struct bpf_prog_info; LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo); LIBBPF_API struct bpf_prog_linfo * bpf_prog_linfo__new(const struct bpf_prog_info *info); LIBBPF_API const struct bpf_line_info * bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo, __u64 addr, __u32 func_idx, __u32 nr_skip); LIBBPF_API const struct bpf_line_info * bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo, __u32 insn_off, __u32 nr_skip); /* * Probe for supported system features * * Note that running many of these probes in a short amount of time can cause * the kernel to reach the maximal size of lockable memory allowed for the * user, causing subsequent probes to fail. In this case, the caller may want * to adjust that limit with setrlimit(). */ /** * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports * BPF programs of a given type. * @param prog_type BPF program type to detect kernel support for * @param opts reserved for future extensibility, should be NULL * @return 1, if given program type is supported; 0, if given program type is * not supported; negative error code if feature detection failed or can't be * performed * * Make sure the process has required set of CAP_* permissions (or runs as * root) when performing feature checking. */ LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts); /** * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports * BPF maps of a given type. * @param map_type BPF map type to detect kernel support for * @param opts reserved for future extensibility, should be NULL * @return 1, if given map type is supported; 0, if given map type is * not supported; negative error code if feature detection failed or can't be * performed * * Make sure the process has required set of CAP_* permissions (or runs as * root) when performing feature checking. */ LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts); /** * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the * use of a given BPF helper from specified BPF program type. * @param prog_type BPF program type used to check the support of BPF helper * @param helper_id BPF helper ID (enum bpf_func_id) to check support for * @param opts reserved for future extensibility, should be NULL * @return 1, if given combination of program type and helper is supported; 0, * if the combination is not supported; negative error code if feature * detection for provided input arguments failed or can't be performed * * Make sure the process has required set of CAP_* permissions (or runs as * root) when performing feature checking. */ LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type, enum bpf_func_id helper_id, const void *opts); /** * @brief **libbpf_num_possible_cpus()** is a helper function to get the * number of possible CPUs that the host kernel supports and expects. * @return number of possible CPUs; or error code on failure * * Example usage: * * int ncpus = libbpf_num_possible_cpus(); * if (ncpus < 0) { * // error handling * } * long values[ncpus]; * bpf_map_lookup_elem(per_cpu_map_fd, key, values); */ LIBBPF_API int libbpf_num_possible_cpus(void); struct bpf_map_skeleton { const char *name; struct bpf_map **map; void **mmaped; struct bpf_link **link; }; struct bpf_prog_skeleton { const char *name; struct bpf_program **prog; struct bpf_link **link; }; struct bpf_object_skeleton { size_t sz; /* size of this struct, for forward/backward compatibility */ const char *name; const void *data; size_t data_sz; struct bpf_object **obj; int map_cnt; int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ struct bpf_map_skeleton *maps; int prog_cnt; int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ struct bpf_prog_skeleton *progs; }; LIBBPF_API int bpf_object__open_skeleton(struct bpf_object_skeleton *s, const struct bpf_object_open_opts *opts); LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s); LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s); LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s); LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s); struct bpf_var_skeleton { const char *name; struct bpf_map **map; void **addr; }; struct bpf_object_subskeleton { size_t sz; /* size of this struct, for forward/backward compatibility */ const struct bpf_object *obj; int map_cnt; int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */ struct bpf_map_skeleton *maps; int prog_cnt; int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */ struct bpf_prog_skeleton *progs; int var_cnt; int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */ struct bpf_var_skeleton *vars; }; LIBBPF_API int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s); LIBBPF_API void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s); struct gen_loader_opts { size_t sz; /* size of this struct, for forward/backward compatibility */ const char *data; const char *insns; __u32 data_sz; __u32 insns_sz; }; #define gen_loader_opts__last_field insns_sz LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj, struct gen_loader_opts *opts); enum libbpf_tristate { TRI_NO = 0, TRI_YES = 1, TRI_MODULE = 2, }; struct bpf_linker_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; }; #define bpf_linker_opts__last_field sz struct bpf_linker_file_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; }; #define bpf_linker_file_opts__last_field sz struct bpf_linker; LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts); LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker, const char *filename, const struct bpf_linker_file_opts *opts); LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker); LIBBPF_API void bpf_linker__free(struct bpf_linker *linker); /* * Custom handling of BPF program's SEC() definitions */ struct bpf_prog_load_opts; /* defined in bpf.h */ /* Called during bpf_object__open() for each recognized BPF program. Callback * can use various bpf_program__set_*() setters to adjust whatever properties * are necessary. */ typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie); /* Called right before libbpf performs bpf_prog_load() to load BPF program * into the kernel. Callback can adjust opts as necessary. */ typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog, struct bpf_prog_load_opts *opts, long cookie); /* Called during skeleton attach or through bpf_program__attach(). If * auto-attach is not supported, callback should return 0 and set link to * NULL (it's not considered an error during skeleton attach, but it will be * an error for bpf_program__attach() calls). On error, error should be * returned directly and link set to NULL. On success, return 0 and set link * to a valid struct bpf_link. */ typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie, struct bpf_link **link); struct libbpf_prog_handler_opts { /* size of this struct, for forward/backward compatibility */ size_t sz; /* User-provided value that is passed to prog_setup_fn, * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to * register one set of callbacks for multiple SEC() definitions and * still be able to distinguish them, if necessary. For example, * libbpf itself is using this to pass necessary flags (e.g., * sleepable flag) to a common internal SEC() handler. */ long cookie; /* BPF program initialization callback (see libbpf_prog_setup_fn_t). * Callback is optional, pass NULL if it's not necessary. */ libbpf_prog_setup_fn_t prog_setup_fn; /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t). * Callback is optional, pass NULL if it's not necessary. */ libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; /* BPF program attach callback (see libbpf_prog_attach_fn_t). * Callback is optional, pass NULL if it's not necessary. */ libbpf_prog_attach_fn_t prog_attach_fn; }; #define libbpf_prog_handler_opts__last_field prog_attach_fn /** * @brief **libbpf_register_prog_handler()** registers a custom BPF program * SEC() handler. * @param sec section prefix for which custom handler is registered * @param prog_type BPF program type associated with specified section * @param exp_attach_type Expected BPF attach type associated with specified section * @param opts optional cookie, callbacks, and other extra options * @return Non-negative handler ID is returned on success. This handler ID has * to be passed to *libbpf_unregister_prog_handler()* to unregister such * custom handler. Negative error code is returned on error. * * *sec* defines which SEC() definitions are handled by this custom handler * registration. *sec* can have few different forms: * - if *sec* is just a plain string (e.g., "abc"), it will match only * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result * in an error; * - if *sec* is of the form "abc/", proper SEC() form is * SEC("abc/something"), where acceptable "something" should be checked by * *prog_init_fn* callback, if there are additional restrictions; * - if *sec* is of the form "abc+", it will successfully match both * SEC("abc") and SEC("abc/whatever") forms; * - if *sec* is NULL, custom handler is registered for any BPF program that * doesn't match any of the registered (custom or libbpf's own) SEC() * handlers. There could be only one such generic custom handler registered * at any given time. * * All custom handlers (except the one with *sec* == NULL) are processed * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's * SEC() handlers by registering custom ones for the same section prefix * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses") * handler). * * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs * to ensure synchronization if there is a risk of running this API from * multiple threads simultaneously. */ LIBBPF_API int libbpf_register_prog_handler(const char *sec, enum bpf_prog_type prog_type, enum bpf_attach_type exp_attach_type, const struct libbpf_prog_handler_opts *opts); /** * @brief *libbpf_unregister_prog_handler()* unregisters previously registered * custom BPF program SEC() handler. * @param handler_id handler ID returned by *libbpf_register_prog_handler()* * after successful registration * @return 0 on success, negative error code if handler isn't found * * Note, like much of global libbpf APIs (e.g., libbpf_set_print(), * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs * to ensure synchronization if there is a risk of running this API from * multiple threads simultaneously. */ LIBBPF_API int libbpf_unregister_prog_handler(int handler_id); #ifdef __cplusplus } /* extern "C" */ #endif #endif /* __LIBBPF_LIBBPF_H */