tools/lib/bpf/libbpf.h

   1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
   2
   3 /*
   4  * Common eBPF ELF object loading operations.
   5  *
   6  * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
   7  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   8  * Copyright (C) 2015 Huawei Inc.
   9  */
  10 #ifndef __LIBBPF_LIBBPF_H
  11 #define __LIBBPF_LIBBPF_H
  12
  13 #include <stdarg.h>
  14 #include <stdio.h>
  15 #include <stdint.h>
  16 #include <stdbool.h>
  17 #include <sys/types.h>  // for size_t
  18 #include <linux/bpf.h>
  19
  20 #ifdef __cplusplus
  21 extern "C" {
  22 #endif
  23
  24 #ifndef LIBBPF_API
  25 #define LIBBPF_API __attribute__((visibility("default")))
  26 #endif
  27
  28 enum libbpf_errno {
  29         __LIBBPF_ERRNO__START = 4000,
  30
  31         /* Something wrong in libelf */
  32         LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
  33         LIBBPF_ERRNO__FORMAT,   /* BPF object format invalid */
  34         LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
  35         LIBBPF_ERRNO__ENDIAN,   /* Endian mismatch */
  36         LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
  37         LIBBPF_ERRNO__RELOC,    /* Relocation failed */
  38         LIBBPF_ERRNO__LOAD,     /* Load program failure for unknown reason */
  39         LIBBPF_ERRNO__VERIFY,   /* Kernel verifier blocks program loading */
  40         LIBBPF_ERRNO__PROG2BIG, /* Program too big */
  41         LIBBPF_ERRNO__KVER,     /* Incorrect kernel version */
  42         LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
  43         LIBBPF_ERRNO__WRNGPID,  /* Wrong pid in netlink message */
  44         LIBBPF_ERRNO__INVSEQ,   /* Invalid netlink sequence */
  45         LIBBPF_ERRNO__NLPARSE,  /* netlink parsing error */
  46         __LIBBPF_ERRNO__END,
  47 };
  48
  49 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
  50
  51 enum libbpf_print_level {
  52         LIBBPF_WARN,
  53         LIBBPF_INFO,
  54         LIBBPF_DEBUG,
  55 };
  56
  57 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
  58                                  const char *, va_list ap);
  59
  60 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
  61
  62 /* Hide internal to user */
  63 struct bpf_object;
  64
  65 struct bpf_object_open_attr {
  66         const char *file;
  67         enum bpf_prog_type prog_type;
  68 };
  69
  70 /* Helper macro to declare and initialize libbpf options struct
  71  *
  72  * This dance with uninitialized declaration, followed by memset to zero,
  73  * followed by assignment using compound literal syntax is done to preserve
  74  * ability to use a nice struct field initialization syntax and **hopefully**
  75  * have all the padding bytes initialized to zero. It's not guaranteed though,
  76  * when copying literal, that compiler won't copy garbage in literal's padding
  77  * bytes, but that's the best way I've found and it seems to work in practice.
  78  *
  79  * Macro declares opts struct of given type and name, zero-initializes,
  80  * including any extra padding, it with memset() and then assigns initial
  81  * values provided by users in struct initializer-syntax as varargs.
  82  */
  83 #define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)                                \
  84         struct TYPE NAME = ({                                               \
  85                 memset(&NAME, 0, sizeof(struct TYPE));                      \
  86                 (struct TYPE) {                                             \
  87                         .sz = sizeof(struct TYPE),                          \
  88                         __VA_ARGS__                                         \
  89                 };                                                          \
  90         })
  91
  92 struct bpf_object_open_opts {
  93         /* size of this struct, for forward/backward compatiblity */
  94         size_t sz;
  95         /* object name override, if provided:
  96          * - for object open from file, this will override setting object
  97          *   name from file path's base name;
  98          * - for object open from memory buffer, this will specify an object
  99          *   name and will override default "<addr>-<buf-size>" name;
 100          */
 101         const char *object_name;
 102         /* parse map definitions non-strictly, allowing extra attributes/data */
 103         bool relaxed_maps;
 104         /* process CO-RE relocations non-strictly, allowing them to fail */
 105         bool relaxed_core_relocs;
 106         /* maps that set the 'pinning' attribute in their definition will have
 107          * their pin_path attribute set to a file in this directory, and be
 108          * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
 109          */
 110         const char *pin_root_path;
 111         __u32 attach_prog_fd;
 112 };
 113 #define bpf_object_open_opts__last_field attach_prog_fd
 114
 115 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
 116 LIBBPF_API struct bpf_object *
 117 bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts);
 118 LIBBPF_API struct bpf_object *
 119 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
 120                      struct bpf_object_open_opts *opts);
 121
 122 /* deprecated bpf_object__open variants */
 123 LIBBPF_API struct bpf_object *
 124 bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
 125                         const char *name);
 126 LIBBPF_API struct bpf_object *
 127 bpf_object__open_xattr(struct bpf_object_open_attr *attr);
 128
 129 enum libbpf_pin_type {
 130         LIBBPF_PIN_NONE,
 131         /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
 132         LIBBPF_PIN_BY_NAME,
 133 };
 134
 135 /* pin_maps and unpin_maps can both be called with a NULL path, in which case
 136  * they will use the pin_path attribute of each map (and ignore all maps that
 137  * don't have a pin_path set).
 138  */
 139 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
 140 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
 141                                       const char *path);
 142 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
 143                                         const char *path);
 144 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
 145                                           const char *path);
 146 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
 147 LIBBPF_API void bpf_object__close(struct bpf_object *object);
 148
 149 struct bpf_object_load_attr {
 150         struct bpf_object *obj;
 151         int log_level;
 152         const char *target_btf_path;
 153 };
 154
 155 /* Load/unload object into/from kernel */
 156 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 157 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
 158 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
 159 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
 160 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
 161
 162 struct btf;
 163 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
 164 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
 165
 166 LIBBPF_API struct bpf_program *
 167 bpf_object__find_program_by_title(const struct bpf_object *obj,
 168                                   const char *title);
 169
 170 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
 171 #define bpf_object__for_each_safe(pos, tmp)                     \
 172         for ((pos) = bpf_object__next(NULL),            \
 173                 (tmp) = bpf_object__next(pos);          \
 174              (pos) != NULL;                             \
 175              (pos) = (tmp), (tmp) = bpf_object__next(tmp))
 176
 177 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
 178 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
 179                                     bpf_object_clear_priv_t clear_priv);
 180 LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);
 181
 182 LIBBPF_API int
 183 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 184                          enum bpf_attach_type *expected_attach_type);
 185 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
 186                                           enum bpf_attach_type *attach_type);
 187 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
 188                                           enum bpf_attach_type attach_type);
 189
 190 /* Accessors of bpf_program */
 191 struct bpf_program;
 192 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
 193                                                  const struct bpf_object *obj);
 194
 195 #define bpf_object__for_each_program(pos, obj)          \
 196         for ((pos) = bpf_program__next(NULL, (obj));    \
 197              (pos) != NULL;                             \
 198              (pos) = bpf_program__next((pos), (obj)))
 199
 200 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
 201                                                  const struct bpf_object *obj);
 202
 203 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
 204
 205 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
 206                                      bpf_program_clear_priv_t clear_priv);
 207
 208 LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
 209 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
 210                                          __u32 ifindex);
 211
 212 LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
 213                                           bool needs_copy);
 214
 215 /* returns program size in bytes */
 216 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
 217
 218 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
 219                                  __u32 kern_version);
 220 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
 221 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
 222                                          const char *path,
 223                                          int instance);
 224 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
 225                                            const char *path,
 226                                            int instance);
 227 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
 228 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
 229 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
 230
 231 struct bpf_link;
 232
 233 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 234
 235 LIBBPF_API struct bpf_link *
 236 bpf_program__attach(struct bpf_program *prog);
 237 LIBBPF_API struct bpf_link *
 238 bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
 239 LIBBPF_API struct bpf_link *
 240 bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
 241                            const char *func_name);
 242 LIBBPF_API struct bpf_link *
 243 bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
 244                            pid_t pid, const char *binary_path,
 245                            size_t func_offset);
 246 LIBBPF_API struct bpf_link *
 247 bpf_program__attach_tracepoint(struct bpf_program *prog,
 248                                const char *tp_category,
 249                                const char *tp_name);
 250 LIBBPF_API struct bpf_link *
 251 bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
 252                                    const char *tp_name);
 253
 254 LIBBPF_API struct bpf_link *
 255 bpf_program__attach_trace(struct bpf_program *prog);
 256 struct bpf_insn;
 257
 258 /*
 259  * Libbpf allows callers to adjust BPF programs before being loaded
 260  * into kernel. One program in an object file can be transformed into
 261  * multiple variants to be attached to different hooks.
 262  *
 263  * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
 264  * form an API for this purpose.
 265  *
 266  * - bpf_program_prep_t:
 267  *   Defines a 'preprocessor', which is a caller defined function
 268  *   passed to libbpf through bpf_program__set_prep(), and will be
 269  *   called before program is loaded. The processor should adjust
 270  *   the program one time for each instance according to the instance id
 271  *   passed to it.
 272  *
 273  * - bpf_program__set_prep:
 274  *   Attaches a preprocessor to a BPF program. The number of instances
 275  *   that should be created is also passed through this function.
 276  *
 277  * - bpf_program__nth_fd:
 278  *   After the program is loaded, get resulting FD of a given instance
 279  *   of the BPF program.
 280  *
 281  * If bpf_program__set_prep() is not used, the program would be loaded
 282  * without adjustment during bpf_object__load(). The program has only
 283  * one instance. In this case bpf_program__fd(prog) is equal to
 284  * bpf_program__nth_fd(prog, 0).
 285  */
 286
 287 struct bpf_prog_prep_result {
 288         /*
 289          * If not NULL, load new instruction array.
 290          * If set to NULL, don't load this instance.
 291          */
 292         struct bpf_insn *new_insn_ptr;
 293         int new_insn_cnt;
 294
 295         /* If not NULL, result FD is written to it. */
 296         int *pfd;
 297 };
 298
 299 /*
 300  * Parameters of bpf_program_prep_t:
 301  *  - prog:     The bpf_program being loaded.
 302  *  - n:        Index of instance being generated.
 303  *  - insns:    BPF instructions array.
 304  *  - insns_cnt:Number of instructions in insns.
 305  *  - res:      Output parameter, result of transformation.
 306  *
 307  * Return value:
 308  *  - Zero:     pre-processing success.
 309  *  - Non-zero: pre-processing error, stop loading.
 310  */
 311 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
 312                                   struct bpf_insn *insns, int insns_cnt,
 313                                   struct bpf_prog_prep_result *res);
 314
 315 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
 316                                      bpf_program_prep_t prep);
 317
 318 LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
 319
 320 /*
 321  * Adjust type of BPF program. Default is kprobe.
 322  */
 323 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
 324 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
 325 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
 326 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
 327 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
 328 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
 329 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
 330 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
 331 LIBBPF_API int bpf_program__set_tracing(struct bpf_program *prog);
 332
 333 LIBBPF_API enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog);
 334 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
 335                                       enum bpf_prog_type type);
 336
 337 LIBBPF_API enum bpf_attach_type
 338 bpf_program__get_expected_attach_type(struct bpf_program *prog);
 339 LIBBPF_API void
 340 bpf_program__set_expected_attach_type(struct bpf_program *prog,
 341                                       enum bpf_attach_type type);
 342
 343 LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
 344 LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
 345 LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
 346 LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
 347 LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
 348 LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
 349 LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
 350 LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
 351 LIBBPF_API bool bpf_program__is_tracing(const struct bpf_program *prog);
 352
 353 /*
 354  * No need for __attribute__((packed)), all members of 'bpf_map_def'
 355  * are all aligned.  In addition, using __attribute__((packed))
 356  * would trigger a -Wpacked warning message, and lead to an error
 357  * if -Werror is set.
 358  */
 359 struct bpf_map_def {
 360         unsigned int type;
 361         unsigned int key_size;
 362         unsigned int value_size;
 363         unsigned int max_entries;
 364         unsigned int map_flags;
 365 };
 366
 367 /*
 368  * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
 369  * so no need to worry about a name clash.
 370  */
 371 struct bpf_map;
 372 LIBBPF_API struct bpf_map *
 373 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
 374
 375 LIBBPF_API int
 376 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
 377
 378 /*
 379  * Get bpf_map through the offset of corresponding struct bpf_map_def
 380  * in the BPF object file.
 381  */
 382 LIBBPF_API struct bpf_map *
 383 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
 384
 385 LIBBPF_API struct bpf_map *
 386 bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
 387 #define bpf_object__for_each_map(pos, obj)              \
 388         for ((pos) = bpf_map__next(NULL, (obj));        \
 389              (pos) != NULL;                             \
 390              (pos) = bpf_map__next((pos), (obj)))
 391 #define bpf_map__for_each bpf_object__for_each_map
 392
 393 LIBBPF_API struct bpf_map *
 394 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
 395
 396 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
 397 LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
 398 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
 399 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
 400 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
 401
 402 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
 403 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
 404                                  bpf_map_clear_priv_t clear_priv);
 405 LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
 406 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 407 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
 408 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
 409 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 410 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
 411 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
 412 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
 413 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
 414 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
 415 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 416
 417 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 418
 419 LIBBPF_API long libbpf_get_error(const void *ptr);
 420
 421 struct bpf_prog_load_attr {
 422         const char *file;
 423         enum bpf_prog_type prog_type;
 424         enum bpf_attach_type expected_attach_type;
 425         int ifindex;
 426         int log_level;
 427         int prog_flags;
 428 };
 429
 430 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 431                                    struct bpf_object **pobj, int *prog_fd);
 432 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
 433                              struct bpf_object **pobj, int *prog_fd);
 434
 435 struct xdp_link_info {
 436         __u32 prog_id;
 437         __u32 drv_prog_id;
 438         __u32 hw_prog_id;
 439         __u32 skb_prog_id;
 440         __u8 attach_mode;
 441 };
 442
 443 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
 444 LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
 445 LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
 446                                      size_t info_size, __u32 flags);
 447
 448 struct perf_buffer;
 449
 450 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
 451                                       void *data, __u32 size);
 452 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
 453
 454 /* common use perf buffer options */
 455 struct perf_buffer_opts {
 456         /* if specified, sample_cb is called for each sample */
 457         perf_buffer_sample_fn sample_cb;
 458         /* if specified, lost_cb is called for each batch of lost samples */
 459         perf_buffer_lost_fn lost_cb;
 460         /* ctx is provided to sample_cb and lost_cb */
 461         void *ctx;
 462 };
 463
 464 LIBBPF_API struct perf_buffer *
 465 perf_buffer__new(int map_fd, size_t page_cnt,
 466                  const struct perf_buffer_opts *opts);
 467
 468 enum bpf_perf_event_ret {
 469         LIBBPF_PERF_EVENT_DONE  = 0,
 470         LIBBPF_PERF_EVENT_ERROR = -1,
 471         LIBBPF_PERF_EVENT_CONT  = -2,
 472 };
 473
 474 struct perf_event_header;
 475
 476 typedef enum bpf_perf_event_ret
 477 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
 478
 479 /* raw perf buffer options, giving most power and control */
 480 struct perf_buffer_raw_opts {
 481         /* perf event attrs passed directly into perf_event_open() */
 482         struct perf_event_attr *attr;
 483         /* raw event callback */
 484         perf_buffer_event_fn event_cb;
 485         /* ctx is provided to event_cb */
 486         void *ctx;
 487         /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
 488          * max_entries of given PERF_EVENT_ARRAY map)
 489          */
 490         int cpu_cnt;
 491         /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
 492         int *cpus;
 493         /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
 494         int *map_keys;
 495 };
 496
 497 LIBBPF_API struct perf_buffer *
 498 perf_buffer__new_raw(int map_fd, size_t page_cnt,
 499                      const struct perf_buffer_raw_opts *opts);
 500
 501 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
 502 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
 503
 504 typedef enum bpf_perf_event_ret
 505         (*bpf_perf_event_print_t)(struct perf_event_header *hdr,
 506                                   void *private_data);
 507 LIBBPF_API enum bpf_perf_event_ret
 508 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
 509                            void **copy_mem, size_t *copy_size,
 510                            bpf_perf_event_print_t fn, void *private_data);
 511
 512 struct bpf_prog_linfo;
 513 struct bpf_prog_info;
 514
 515 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
 516 LIBBPF_API struct bpf_prog_linfo *
 517 bpf_prog_linfo__new(const struct bpf_prog_info *info);
 518 LIBBPF_API const struct bpf_line_info *
 519 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
 520                                 __u64 addr, __u32 func_idx, __u32 nr_skip);
 521 LIBBPF_API const struct bpf_line_info *
 522 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
 523                       __u32 insn_off, __u32 nr_skip);
 524
 525 /*
 526  * Probe for supported system features
 527  *
 528  * Note that running many of these probes in a short amount of time can cause
 529  * the kernel to reach the maximal size of lockable memory allowed for the
 530  * user, causing subsequent probes to fail. In this case, the caller may want
 531  * to adjust that limit with setrlimit().
 532  */
 533 LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
 534                                     __u32 ifindex);
 535 LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
 536 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
 537                                  enum bpf_prog_type prog_type, __u32 ifindex);
 538
 539 /*
 540  * Get bpf_prog_info in continuous memory
 541  *
 542  * struct bpf_prog_info has multiple arrays. The user has option to choose
 543  * arrays to fetch from kernel. The following APIs provide an uniform way to
 544  * fetch these data. All arrays in bpf_prog_info are stored in a single
 545  * continuous memory region. This makes it easy to store the info in a
 546  * file.
 547  *
 548  * Before writing bpf_prog_info_linear to files, it is necessary to
 549  * translate pointers in bpf_prog_info to offsets. Helper functions
 550  * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
 551  * are introduced to switch between pointers and offsets.
 552  *
 553  * Examples:
 554  *   # To fetch map_ids and prog_tags:
 555  *   __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
 556  *           (1UL << BPF_PROG_INFO_PROG_TAGS);
 557  *   struct bpf_prog_info_linear *info_linear =
 558  *           bpf_program__get_prog_info_linear(fd, arrays);
 559  *
 560  *   # To save data in file
 561  *   bpf_program__bpil_addr_to_offs(info_linear);
 562  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
 563  *
 564  *   # To read data from file
 565  *   read(f, info_linear, <proper_size>);
 566  *   bpf_program__bpil_offs_to_addr(info_linear);
 567  */
 568 enum bpf_prog_info_array {
 569         BPF_PROG_INFO_FIRST_ARRAY = 0,
 570         BPF_PROG_INFO_JITED_INSNS = 0,
 571         BPF_PROG_INFO_XLATED_INSNS,
 572         BPF_PROG_INFO_MAP_IDS,
 573         BPF_PROG_INFO_JITED_KSYMS,
 574         BPF_PROG_INFO_JITED_FUNC_LENS,
 575         BPF_PROG_INFO_FUNC_INFO,
 576         BPF_PROG_INFO_LINE_INFO,
 577         BPF_PROG_INFO_JITED_LINE_INFO,
 578         BPF_PROG_INFO_PROG_TAGS,
 579         BPF_PROG_INFO_LAST_ARRAY,
 580 };
 581
 582 struct bpf_prog_info_linear {
 583         /* size of struct bpf_prog_info, when the tool is compiled */
 584         __u32                   info_len;
 585         /* total bytes allocated for data, round up to 8 bytes */
 586         __u32                   data_len;
 587         /* which arrays are included in data */
 588         __u64                   arrays;
 589         struct bpf_prog_info    info;
 590         __u8                    data[];
 591 };
 592
 593 LIBBPF_API struct bpf_prog_info_linear *
 594 bpf_program__get_prog_info_linear(int fd, __u64 arrays);
 595
 596 LIBBPF_API void
 597 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
 598
 599 LIBBPF_API void
 600 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
 601
 602 /*
 603  * A helper function to get the number of possible CPUs before looking up
 604  * per-CPU maps. Negative errno is returned on failure.
 605  *
 606  * Example usage:
 607  *
 608  *     int ncpus = libbpf_num_possible_cpus();
 609  *     if (ncpus < 0) {
 610  *          // error handling
 611  *     }
 612  *     long values[ncpus];
 613  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
 614  *
 615  */
 616 LIBBPF_API int libbpf_num_possible_cpus(void);
 617
 618 struct bpf_embed_data {
 619         void *data;
 620         size_t size;
 621 };
 622
 623 #define BPF_EMBED_OBJ_DECLARE(NAME)                                     \
 624 extern struct bpf_embed_data NAME##_embed;                              \
 625 extern char NAME##_data[];                                              \
 626 extern char NAME##_data_end[];
 627
 628 #define __BPF_EMBED_OBJ(NAME, PATH, SZ, ASM_TYPE)                       \
 629 asm (                                                                   \
 630 "       .pushsection \".rodata\", \"a\", @progbits              \n"     \
 631 "       .global "#NAME"_data                                    \n"     \
 632 #NAME"_data:                                                    \n"     \
 633 "       .incbin \"" PATH "\"                                    \n"     \
 634 "       .global "#NAME"_data_end                                \n"     \
 635 #NAME"_data_end:                                                \n"     \
 636 "       .global "#NAME"_embed                                   \n"     \
 637 "       .type "#NAME"_embed, @object                            \n"     \
 638 "       .size "#NAME"_size, "#SZ"                               \n"     \
 639 "       .align 8,                                               \n"     \
 640 #NAME"_embed:                                                   \n"     \
 641 "       "ASM_TYPE" "#NAME"_data                                 \n"     \
 642 "       "ASM_TYPE" "#NAME"_data_end - "#NAME"_data              \n"     \
 643 "       .popsection                                             \n"     \
 644 );                                                                      \
 645 BPF_EMBED_OBJ_DECLARE(NAME)
 646
 647 #if __SIZEOF_POINTER__ == 4
 648 #define BPF_EMBED_OBJ(NAME, PATH) __BPF_EMBED_OBJ(NAME, PATH, 8, ".long")
 649 #else
 650 #define BPF_EMBED_OBJ(NAME, PATH) __BPF_EMBED_OBJ(NAME, PATH, 16, ".quad")
 651 #endif
 652
 653 #ifdef __cplusplus
 654 } /* extern "C" */
 655 #endif
 656
 657 #endif /* __LIBBPF_LIBBPF_H */