TOMOYO Linux Cross Reference
Linux/tools/lib/bpf/libbpf.h

   /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
   
   /*
    * Common eBPF ELF object loading operations.
    *
    * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
    * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
    * Copyright (C) 2015 Huawei Inc.
    */
  #ifndef __LIBBPF_LIBBPF_H
  #define __LIBBPF_LIBBPF_H
  
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdint.h>
  #include <stdbool.h>
  #include <sys/types.h>  // for size_t
  #include <linux/bpf.h>
  
  #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 "<addr>-<buf-size>" 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 overriden
          *     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);
 
 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 paremeters, 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;
         size_t :0;
 };
 
 #define bpf_uprobe_multi_opts__last_field retprobe
 
 /**
  * @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 __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
  * attach specified program using kprobe/kretprobe mechanism.
  *
  * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
  * **SEC("ksyscall/<syscall>")** 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 proccess 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 managment 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 retreive
  * @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 */
 

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.