diff options
Diffstat (limited to 'src/bpfswitch/include/bpf/btf.h')
-rw-r--r-- | src/bpfswitch/include/bpf/btf.h | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/src/bpfswitch/include/bpf/btf.h b/src/bpfswitch/include/bpf/btf.h new file mode 100644 index 00000000..a3b7ef9b --- /dev/null +++ b/src/bpfswitch/include/bpf/btf.h @@ -0,0 +1,340 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ +/* Copyright (c) 2018 Facebook */ + +#ifndef __LIBBPF_BTF_H +#define __LIBBPF_BTF_H + +#include <stdarg.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; + +/* + * The .BTF.ext ELF section layout defined as + * struct btf_ext_header + * func_info subsection + * + * The func_info subsection layout: + * record size for struct bpf_func_info in the func_info subsection + * struct btf_sec_func_info for section #1 + * a list of bpf_func_info records for section #1 + * where struct bpf_func_info mimics one in include/uapi/linux/bpf.h + * but may not be identical + * struct btf_sec_func_info for section #2 + * a list of bpf_func_info records for section #2 + * ...... + * + * Note that the bpf_func_info record size in .BTF.ext may not + * be the same as the one defined in include/uapi/linux/bpf.h. + * The loader should ensure that record_size meets minimum + * requirement and pass the record as is to the kernel. The + * kernel will handle the func_info properly based on its contents. + */ +struct btf_ext_header { + __u16 magic; + __u8 version; + __u8 flags; + __u32 hdr_len; + + /* All offsets are in bytes relative to the end of this header */ + __u32 func_info_off; + __u32 func_info_len; + __u32 line_info_off; + __u32 line_info_len; + + /* optional part of .BTF.ext header */ + __u32 field_reloc_off; + __u32 field_reloc_len; +}; + +LIBBPF_API void btf__free(struct btf *btf); +LIBBPF_API struct btf *btf__new(const void *data, __u32 size); +LIBBPF_API struct btf *btf__parse_elf(const char *path, + struct btf_ext **btf_ext); +LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf); +LIBBPF_API int btf__load(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_type *btf__type_by_id(const struct btf *btf, + __u32 id); +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 int btf__get_from_id(__u32 id, struct btf **btf); +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 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 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 struct btf *libbpf_find_kernel_btf(void); + +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; +}; +#define btf_dump_emit_type_decl_opts__last_field indent_level + +LIBBPF_API int +btf_dump__emit_type_decl(struct btf_dump *d, __u32 id, + const struct btf_dump_emit_type_decl_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 __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); +} + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif /* __LIBBPF_BTF_H */ |