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