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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
/* Copyright (c) 2018 Facebook */
/*! \file */
#ifndef __LIBBPF_BTF_H
#define __LIBBPF_BTF_H
#include <stdarg.h>
#include <stdbool.h>
#include <linux/btf.h>
#include <linux/types.h>
#include "libbpf_common.h"
#ifdef __cplusplus
extern "C" {
#endif
#define BTF_ELF_SEC ".BTF"
#define BTF_EXT_ELF_SEC ".BTF.ext"
#define MAPS_ELF_SEC ".maps"
struct btf;
struct btf_ext;
struct btf_type;
struct bpf_object;
enum btf_endianness {
BTF_LITTLE_ENDIAN = 0,
BTF_BIG_ENDIAN = 1,
};
/**
* @brief **btf__free()** frees all data of a BTF object
* @param btf BTF object to free
*/
LIBBPF_API void btf__free(struct btf *btf);
/**
* @brief **btf__new()** creates a new instance of a BTF object from the raw
* bytes of an ELF's BTF section
* @param data raw bytes
* @param size number of bytes passed in `data`
* @return new BTF object instance which has to be eventually freed with
* **btf__free()**
*
* On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
* error code from such a pointer `libbpf_get_error()` should be used. If
* `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
* returned on error instead. In both cases thread-local `errno` variable is
* always set to error code as well.
*/
LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
/**
* @brief **btf__new_split()** create a new instance of a BTF object from the
* provided raw data bytes. It takes another BTF instance, **base_btf**, which
* serves as a base BTF, which is extended by types in a newly created BTF
* instance
* @param data raw bytes
* @param size length of raw bytes
* @param base_btf the base BTF object
* @return new BTF object instance which has to be eventually freed with
* **btf__free()**
*
* If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and
* creates non-split BTF.
*
* On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
* error code from such a pointer `libbpf_get_error()` should be used. If
* `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
* returned on error instead. In both cases thread-local `errno` variable is
* always set to error code as well.
*/
LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
/**
* @brief **btf__new_empty()** creates an empty BTF object. Use
* `btf__add_*()` to populate such BTF object.
* @return new BTF object instance which has to be eventually freed with
* **btf__free()**
*
* On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
* error code from such a pointer `libbpf_get_error()` should be used. If
* `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
* returned on error instead. In both cases thread-local `errno` variable is
* always set to error code as well.
*/
LIBBPF_API struct btf *btf__new_empty(void);
/**
* @brief **btf__new_empty_split()** creates an unpopulated BTF object from an
* ELF BTF section except with a base BTF on top of which split BTF should be
* based
* @return new BTF object instance which has to be eventually freed with
* **btf__free()**
*
* If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to
* `btf__new_empty()` and creates non-split BTF.
*
* On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
* error code from such a pointer `libbpf_get_error()` should be used. If
* `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
* returned on error instead. In both cases thread-local `errno` variable is
* always set to error code as well.
*/
LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__parse_raw(const char *path);
LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__load_vmlinux_btf(void);
LIBBPF_API struct btf *btf__load_module_btf(const char *module_name, struct btf *vmlinux_btf);
LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API int btf__load_into_kernel(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
const char *type_name);
LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
const char *type_name, __u32 kind);
LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
__u32 id);
LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
LIBBPF_API int btf__fd(const struct btf *btf);
LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
__u32 expected_key_size,
__u32 expected_value_size,
__u32 *key_type_id, __u32 *value_type_id);
LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
__u32 *size);
LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_func_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
int btf_ext__reloc_func_info(const struct btf *btf,
const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **func_info, __u32 *cnt);
LIBBPF_API LIBBPF_DEPRECATED("btf_ext__reloc_line_info was never meant as a public API and has wrong assumptions embedded in it; it will be removed in the future libbpf versions")
int btf_ext__reloc_line_info(const struct btf *btf,
const struct btf_ext *btf_ext,
const char *sec_name, __u32 insns_cnt,
void **line_info, __u32 *cnt);
LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf,
const struct btf_type *src_type);
/**
* @brief **btf__add_btf()** appends all the BTF types from *src_btf* into *btf*
* @param btf BTF object which all the BTF types and strings are added to
* @param src_btf BTF object which all BTF types and referenced strings are copied from
* @return BTF type ID of the first appended BTF type, or negative error code
*
* **btf__add_btf()** can be used to simply and efficiently append the entire
* contents of one BTF object to another one. All the BTF type data is copied
* over, all referenced type IDs are adjusted by adding a necessary ID offset.
* Only strings referenced from BTF types are copied over and deduplicated, so
* if there were some unused strings in *src_btf*, those won't be copied over,
* which is consistent with the general string deduplication semantics of BTF
* writing APIs.
*
* If any error is encountered during this process, the contents of *btf* is
* left intact, which means that **btf__add_btf()** follows the transactional
* semantics and the operation as a whole is all-or-nothing.
*
* *src_btf* has to be non-split BTF, as of now copying types from split BTF
* is not supported and will result in -ENOTSUP error code returned.
*/
LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf);
LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz);
LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_array(struct btf *btf,
int index_type_id, int elem_type_id, __u32 nr_elems);
/* struct/union construction APIs */
LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
__u32 bit_offset, __u32 bit_size);
/* enum construction APIs */
LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
enum btf_fwd_kind {
BTF_FWD_STRUCT = 0,
BTF_FWD_UNION = 1,
BTF_FWD_ENUM = 2,
};
LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
/* func and func_proto construction APIs */
LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
enum btf_func_linkage linkage, int proto_type_id);
LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
/* var & datasec construction APIs */
LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
__u32 offset, __u32 byte_sz);
/* tag construction API */
LIBBPF_API int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
int component_idx);
struct btf_dedup_opts {
unsigned int dedup_table_size;
bool dont_resolve_fwds;
};
LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
const struct btf_dedup_opts *opts);
struct btf_dump;
struct btf_dump_opts {
void *ctx;
};
typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
const struct btf_ext *btf_ext,
const struct btf_dump_opts *opts,
btf_dump_printf_fn_t printf_fn);
LIBBPF_API void btf_dump__free(struct btf_dump *d);
LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
struct btf_dump_emit_type_decl_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
/* optional field name for type declaration, e.g.:
* - struct my_struct <FNAME>
* - void (*<FNAME>)(int)
* - char (*<FNAME>)[123]
*/
const char *field_name;
/* extra indentation level (in number of tabs) to emit for multi-line
* type declarations (e.g., anonymous struct); applies for lines
* starting from the second one (first line is assumed to have
* necessary indentation already
*/
int indent_level;
/* strip all the const/volatile/restrict mods */
bool strip_mods;
size_t :0;
};
#define btf_dump_emit_type_decl_opts__last_field strip_mods
LIBBPF_API int
btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
const struct btf_dump_emit_type_decl_opts *opts);
struct btf_dump_type_data_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
const char *indent_str;
int indent_level;
/* below match "show" flags for bpf_show_snprintf() */
bool compact; /* no newlines/indentation */
bool skip_names; /* skip member/type names */
bool emit_zeroes; /* show 0-valued fields */
size_t :0;
};
#define btf_dump_type_data_opts__last_field emit_zeroes
LIBBPF_API int
btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
const void *data, size_t data_sz,
const struct btf_dump_type_data_opts *opts);
/*
* A set of helpers for easier BTF types handling
*/
static inline __u16 btf_kind(const struct btf_type *t)
{
return BTF_INFO_KIND(t->info);
}
static inline __u16 btf_vlen(const struct btf_type *t)
{
return BTF_INFO_VLEN(t->info);
}
static inline bool btf_kflag(const struct btf_type *t)
{
return BTF_INFO_KFLAG(t->info);
}
static inline bool btf_is_void(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_UNKN;
}
static inline bool btf_is_int(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_INT;
}
static inline bool btf_is_ptr(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_PTR;
}
static inline bool btf_is_array(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_ARRAY;
}
static inline bool btf_is_struct(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_STRUCT;
}
static inline bool btf_is_union(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_UNION;
}
static inline bool btf_is_composite(const struct btf_type *t)
{
__u16 kind = btf_kind(t);
return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
}
static inline bool btf_is_enum(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_ENUM;
}
static inline bool btf_is_fwd(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FWD;
}
static inline bool btf_is_typedef(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_TYPEDEF;
}
static inline bool btf_is_volatile(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_VOLATILE;
}
static inline bool btf_is_const(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_CONST;
}
static inline bool btf_is_restrict(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_RESTRICT;
}
static inline bool btf_is_mod(const struct btf_type *t)
{
__u16 kind = btf_kind(t);
return kind == BTF_KIND_VOLATILE ||
kind == BTF_KIND_CONST ||
kind == BTF_KIND_RESTRICT;
}
static inline bool btf_is_func(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FUNC;
}
static inline bool btf_is_func_proto(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FUNC_PROTO;
}
static inline bool btf_is_var(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_VAR;
}
static inline bool btf_is_datasec(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_DATASEC;
}
static inline bool btf_is_float(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FLOAT;
}
static inline bool btf_is_tag(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_TAG;
}
static inline __u8 btf_int_encoding(const struct btf_type *t)
{
return BTF_INT_ENCODING(*(__u32 *)(t + 1));
}
static inline __u8 btf_int_offset(const struct btf_type *t)
{
return BTF_INT_OFFSET(*(__u32 *)(t + 1));
}
static inline __u8 btf_int_bits(const struct btf_type *t)
{
return BTF_INT_BITS(*(__u32 *)(t + 1));
}
static inline struct btf_array *btf_array(const struct btf_type *t)
{
return (struct btf_array *)(t + 1);
}
static inline struct btf_enum *btf_enum(const struct btf_type *t)
{
return (struct btf_enum *)(t + 1);
}
static inline struct btf_member *btf_members(const struct btf_type *t)
{
return (struct btf_member *)(t + 1);
}
/* Get bit offset of a member with specified index. */
static inline __u32 btf_member_bit_offset(const struct btf_type *t,
__u32 member_idx)
{
const struct btf_member *m = btf_members(t) + member_idx;
bool kflag = btf_kflag(t);
return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
}
/*
* Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
* BTF_KIND_UNION. If member is not a bitfield, zero is returned.
*/
static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
__u32 member_idx)
{
const struct btf_member *m = btf_members(t) + member_idx;
bool kflag = btf_kflag(t);
return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
}
static inline struct btf_param *btf_params(const struct btf_type *t)
{
return (struct btf_param *)(t + 1);
}
static inline struct btf_var *btf_var(const struct btf_type *t)
{
return (struct btf_var *)(t + 1);
}
static inline struct btf_var_secinfo *
btf_var_secinfos(const struct btf_type *t)
{
return (struct btf_var_secinfo *)(t + 1);
}
struct btf_tag;
static inline struct btf_tag *btf_tag(const struct btf_type *t)
{
return (struct btf_tag *)(t + 1);
}
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* __LIBBPF_BTF_H */
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