tools/lib/bpf/btf.h

   1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
   2 /* Copyright (c) 2018 Facebook */
   3
   4 #ifndef __LIBBPF_BTF_H
   5 #define __LIBBPF_BTF_H
   6
   7 #include <stdarg.h>
   8 #include <stdbool.h>
   9 #include <linux/btf.h>
  10 #include <linux/types.h>
  11
  12 #include "libbpf_common.h"
  13
  14 #ifdef __cplusplus
  15 extern "C" {
  16 #endif
  17
  18 #define BTF_ELF_SEC ".BTF"
  19 #define BTF_EXT_ELF_SEC ".BTF.ext"
  20 #define MAPS_ELF_SEC ".maps"
  21
  22 struct btf;
  23 struct btf_ext;
  24 struct btf_type;
  25
  26 struct bpf_object;
  27
  28 enum btf_endianness {
  29         BTF_LITTLE_ENDIAN = 0,
  30         BTF_BIG_ENDIAN = 1,
  31 };
  32
  33 LIBBPF_API void btf__free(struct btf *btf);
  34
  35 LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
  36 LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
  37 LIBBPF_API struct btf *btf__new_empty(void);
  38 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
  39
  40 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
  41 LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
  42 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
  43 LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
  44 LIBBPF_API struct btf *btf__parse_raw(const char *path);
  45 LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
  46
  47 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
  48 LIBBPF_API int btf__load(struct btf *btf);
  49 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
  50                                    const char *type_name);
  51 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
  52                                         const char *type_name, __u32 kind);
  53 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
  54 LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
  55 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
  56                                                   __u32 id);
  57 LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
  58 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
  59 LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
  60 LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
  61 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
  62 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
  63 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
  64 LIBBPF_API int btf__fd(const struct btf *btf);
  65 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
  66 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
  67 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
  68 LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
  69 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
  70 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
  71                                     __u32 expected_key_size,
  72                                     __u32 expected_value_size,
  73                                     __u32 *key_type_id, __u32 *value_type_id);
  74
  75 LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size);
  76 LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext);
  77 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext,
  78                                              __u32 *size);
  79 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")
  80 int btf_ext__reloc_func_info(const struct btf *btf,
  81                              const struct btf_ext *btf_ext,
  82                              const char *sec_name, __u32 insns_cnt,
  83                              void **func_info, __u32 *cnt);
  84 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")
  85 int btf_ext__reloc_line_info(const struct btf *btf,
  86                              const struct btf_ext *btf_ext,
  87                              const char *sec_name, __u32 insns_cnt,
  88                              void **line_info, __u32 *cnt);
  89 LIBBPF_API __u32 btf_ext__func_info_rec_size(const struct btf_ext *btf_ext);
  90 LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
  91
  92 LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
  93
  94 LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
  95 LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
  96
  97 LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
  98 LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
  99 LIBBPF_API int btf__add_array(struct btf *btf,
 100                               int index_type_id, int elem_type_id, __u32 nr_elems);
 101 /* struct/union construction APIs */
 102 LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
 103 LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
 104 LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
 105                               __u32 bit_offset, __u32 bit_size);
 106
 107 /* enum construction APIs */
 108 LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
 109 LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
 110
 111 enum btf_fwd_kind {
 112         BTF_FWD_STRUCT = 0,
 113         BTF_FWD_UNION = 1,
 114         BTF_FWD_ENUM = 2,
 115 };
 116
 117 LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
 118 LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
 119 LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
 120 LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
 121 LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
 122
 123 /* func and func_proto construction APIs */
 124 LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
 125                              enum btf_func_linkage linkage, int proto_type_id);
 126 LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
 127 LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
 128
 129 /* var & datasec construction APIs */
 130 LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
 131 LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
 132 LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
 133                                          __u32 offset, __u32 byte_sz);
 134
 135 struct btf_dedup_opts {
 136         unsigned int dedup_table_size;
 137         bool dont_resolve_fwds;
 138 };
 139
 140 LIBBPF_API int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
 141                           const struct btf_dedup_opts *opts);
 142
 143 struct btf_dump;
 144
 145 struct btf_dump_opts {
 146         void *ctx;
 147 };
 148
 149 typedef void (*btf_dump_printf_fn_t)(void *ctx, const char *fmt, va_list args);
 150
 151 LIBBPF_API struct btf_dump *btf_dump__new(const struct btf *btf,
 152                                           const struct btf_ext *btf_ext,
 153                                           const struct btf_dump_opts *opts,
 154                                           btf_dump_printf_fn_t printf_fn);
 155 LIBBPF_API void btf_dump__free(struct btf_dump *d);
 156
 157 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
 158
 159 struct btf_dump_emit_type_decl_opts {
 160         /* size of this struct, for forward/backward compatiblity */
 161         size_t sz;
 162         /* optional field name for type declaration, e.g.:
 163          * - struct my_struct <FNAME>
 164          * - void (*<FNAME>)(int)
 165          * - char (*<FNAME>)[123]
 166          */
 167         const char *field_name;
 168         /* extra indentation level (in number of tabs) to emit for multi-line
 169          * type declarations (e.g., anonymous struct); applies for lines
 170          * starting from the second one (first line is assumed to have
 171          * necessary indentation already
 172          */
 173         int indent_level;
 174         /* strip all the const/volatile/restrict mods */
 175         bool strip_mods;
 176 };
 177 #define btf_dump_emit_type_decl_opts__last_field strip_mods
 178
 179 LIBBPF_API int
 180 btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
 181                          const struct btf_dump_emit_type_decl_opts *opts);
 182
 183 /*
 184  * A set of helpers for easier BTF types handling
 185  */
 186 static inline __u16 btf_kind(const struct btf_type *t)
 187 {
 188         return BTF_INFO_KIND(t->info);
 189 }
 190
 191 static inline __u16 btf_vlen(const struct btf_type *t)
 192 {
 193         return BTF_INFO_VLEN(t->info);
 194 }
 195
 196 static inline bool btf_kflag(const struct btf_type *t)
 197 {
 198         return BTF_INFO_KFLAG(t->info);
 199 }
 200
 201 static inline bool btf_is_void(const struct btf_type *t)
 202 {
 203         return btf_kind(t) == BTF_KIND_UNKN;
 204 }
 205
 206 static inline bool btf_is_int(const struct btf_type *t)
 207 {
 208         return btf_kind(t) == BTF_KIND_INT;
 209 }
 210
 211 static inline bool btf_is_ptr(const struct btf_type *t)
 212 {
 213         return btf_kind(t) == BTF_KIND_PTR;
 214 }
 215
 216 static inline bool btf_is_array(const struct btf_type *t)
 217 {
 218         return btf_kind(t) == BTF_KIND_ARRAY;
 219 }
 220
 221 static inline bool btf_is_struct(const struct btf_type *t)
 222 {
 223         return btf_kind(t) == BTF_KIND_STRUCT;
 224 }
 225
 226 static inline bool btf_is_union(const struct btf_type *t)
 227 {
 228         return btf_kind(t) == BTF_KIND_UNION;
 229 }
 230
 231 static inline bool btf_is_composite(const struct btf_type *t)
 232 {
 233         __u16 kind = btf_kind(t);
 234
 235         return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
 236 }
 237
 238 static inline bool btf_is_enum(const struct btf_type *t)
 239 {
 240         return btf_kind(t) == BTF_KIND_ENUM;
 241 }
 242
 243 static inline bool btf_is_fwd(const struct btf_type *t)
 244 {
 245         return btf_kind(t) == BTF_KIND_FWD;
 246 }
 247
 248 static inline bool btf_is_typedef(const struct btf_type *t)
 249 {
 250         return btf_kind(t) == BTF_KIND_TYPEDEF;
 251 }
 252
 253 static inline bool btf_is_volatile(const struct btf_type *t)
 254 {
 255         return btf_kind(t) == BTF_KIND_VOLATILE;
 256 }
 257
 258 static inline bool btf_is_const(const struct btf_type *t)
 259 {
 260         return btf_kind(t) == BTF_KIND_CONST;
 261 }
 262
 263 static inline bool btf_is_restrict(const struct btf_type *t)
 264 {
 265         return btf_kind(t) == BTF_KIND_RESTRICT;
 266 }
 267
 268 static inline bool btf_is_mod(const struct btf_type *t)
 269 {
 270         __u16 kind = btf_kind(t);
 271
 272         return kind == BTF_KIND_VOLATILE ||
 273                kind == BTF_KIND_CONST ||
 274                kind == BTF_KIND_RESTRICT;
 275 }
 276
 277 static inline bool btf_is_func(const struct btf_type *t)
 278 {
 279         return btf_kind(t) == BTF_KIND_FUNC;
 280 }
 281
 282 static inline bool btf_is_func_proto(const struct btf_type *t)
 283 {
 284         return btf_kind(t) == BTF_KIND_FUNC_PROTO;
 285 }
 286
 287 static inline bool btf_is_var(const struct btf_type *t)
 288 {
 289         return btf_kind(t) == BTF_KIND_VAR;
 290 }
 291
 292 static inline bool btf_is_datasec(const struct btf_type *t)
 293 {
 294         return btf_kind(t) == BTF_KIND_DATASEC;
 295 }
 296
 297 static inline __u8 btf_int_encoding(const struct btf_type *t)
 298 {
 299         return BTF_INT_ENCODING(*(__u32 *)(t + 1));
 300 }
 301
 302 static inline __u8 btf_int_offset(const struct btf_type *t)
 303 {
 304         return BTF_INT_OFFSET(*(__u32 *)(t + 1));
 305 }
 306
 307 static inline __u8 btf_int_bits(const struct btf_type *t)
 308 {
 309         return BTF_INT_BITS(*(__u32 *)(t + 1));
 310 }
 311
 312 static inline struct btf_array *btf_array(const struct btf_type *t)
 313 {
 314         return (struct btf_array *)(t + 1);
 315 }
 316
 317 static inline struct btf_enum *btf_enum(const struct btf_type *t)
 318 {
 319         return (struct btf_enum *)(t + 1);
 320 }
 321
 322 static inline struct btf_member *btf_members(const struct btf_type *t)
 323 {
 324         return (struct btf_member *)(t + 1);
 325 }
 326
 327 /* Get bit offset of a member with specified index. */
 328 static inline __u32 btf_member_bit_offset(const struct btf_type *t,
 329                                           __u32 member_idx)
 330 {
 331         const struct btf_member *m = btf_members(t) + member_idx;
 332         bool kflag = btf_kflag(t);
 333
 334         return kflag ? BTF_MEMBER_BIT_OFFSET(m->offset) : m->offset;
 335 }
 336 /*
 337  * Get bitfield size of a member, assuming t is BTF_KIND_STRUCT or
 338  * BTF_KIND_UNION. If member is not a bitfield, zero is returned.
 339  */
 340 static inline __u32 btf_member_bitfield_size(const struct btf_type *t,
 341                                              __u32 member_idx)
 342 {
 343         const struct btf_member *m = btf_members(t) + member_idx;
 344         bool kflag = btf_kflag(t);
 345
 346         return kflag ? BTF_MEMBER_BITFIELD_SIZE(m->offset) : 0;
 347 }
 348
 349 static inline struct btf_param *btf_params(const struct btf_type *t)
 350 {
 351         return (struct btf_param *)(t + 1);
 352 }
 353
 354 static inline struct btf_var *btf_var(const struct btf_type *t)
 355 {
 356         return (struct btf_var *)(t + 1);
 357 }
 358
 359 static inline struct btf_var_secinfo *
 360 btf_var_secinfos(const struct btf_type *t)
 361 {
 362         return (struct btf_var_secinfo *)(t + 1);
 363 }
 364
 365 #ifdef __cplusplus
 366 } /* extern "C" */
 367 #endif
 368
 369 #endif /* __LIBBPF_BTF_H */