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 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 130                              __u32 *size);
 131 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
 132                                 __u32 *off);
 133
 134 enum libbpf_pin_type {
 135         LIBBPF_PIN_NONE,
 136         /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
 137         LIBBPF_PIN_BY_NAME,
 138 };
 139
 140 /* pin_maps and unpin_maps can both be called with a NULL path, in which case
 141  * they will use the pin_path attribute of each map (and ignore all maps that
 142  * don't have a pin_path set).
 143  */
 144 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
 145 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
 146                                       const char *path);
 147 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
 148                                         const char *path);
 149 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
 150                                           const char *path);
 151 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
 152 LIBBPF_API void bpf_object__close(struct bpf_object *object);
 153
 154 struct bpf_object_load_attr {
 155         struct bpf_object *obj;
 156         int log_level;
 157         const char *target_btf_path;
 158 };
 159
 160 /* Load/unload object into/from kernel */
 161 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 162 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
 163 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
 164 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
 165 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
 166
 167 struct btf;
 168 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
 169 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
 170
 171 LIBBPF_API struct bpf_program *
 172 bpf_object__find_program_by_title(const struct bpf_object *obj,
 173                                   const char *title);
 174
 175 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
 176 #define bpf_object__for_each_safe(pos, tmp)                     \
 177         for ((pos) = bpf_object__next(NULL),            \
 178                 (tmp) = bpf_object__next(pos);          \
 179              (pos) != NULL;                             \
 180              (pos) = (tmp), (tmp) = bpf_object__next(tmp))
 181
 182 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
 183 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
 184                                     bpf_object_clear_priv_t clear_priv);
 185 LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);
 186
 187 LIBBPF_API int
 188 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 189                          enum bpf_attach_type *expected_attach_type);
 190 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
 191                                           enum bpf_attach_type *attach_type);
 192 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
 193                                           enum bpf_attach_type attach_type);
 194
 195 /* Accessors of bpf_program */
 196 struct bpf_program;
 197 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
 198                                                  const struct bpf_object *obj);
 199
 200 #define bpf_object__for_each_program(pos, obj)          \
 201         for ((pos) = bpf_program__next(NULL, (obj));    \
 202              (pos) != NULL;                             \
 203              (pos) = bpf_program__next((pos), (obj)))
 204
 205 LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
 206                                                  const struct bpf_object *obj);
 207
 208 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
 209
 210 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
 211                                      bpf_program_clear_priv_t clear_priv);
 212
 213 LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
 214 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
 215                                          __u32 ifindex);
 216
 217 LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
 218                                           bool needs_copy);
 219
 220 /* returns program size in bytes */
 221 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
 222
 223 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
 224                                  __u32 kern_version);
 225 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
 226 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
 227                                          const char *path,
 228                                          int instance);
 229 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
 230                                            const char *path,
 231                                            int instance);
 232 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
 233 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
 234 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
 235
 236 struct bpf_link;
 237
 238 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 239
 240 LIBBPF_API struct bpf_link *
 241 bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
 242 LIBBPF_API struct bpf_link *
 243 bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
 244                            const char *func_name);
 245 LIBBPF_API struct bpf_link *
 246 bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
 247                            pid_t pid, const char *binary_path,
 248                            size_t func_offset);
 249 LIBBPF_API struct bpf_link *
 250 bpf_program__attach_tracepoint(struct bpf_program *prog,
 251                                const char *tp_category,
 252                                const char *tp_name);
 253 LIBBPF_API struct bpf_link *
 254 bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
 255                                    const char *tp_name);
 256
 257 LIBBPF_API struct bpf_link *
 258 bpf_program__attach_trace(struct bpf_program *prog);
 259 struct bpf_insn;
 260
 261 /*
 262  * Libbpf allows callers to adjust BPF programs before being loaded
 263  * into kernel. One program in an object file can be transformed into
 264  * multiple variants to be attached to different hooks.
 265  *
 266  * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
 267  * form an API for this purpose.
 268  *
 269  * - bpf_program_prep_t:
 270  *   Defines a 'preprocessor', which is a caller defined function
 271  *   passed to libbpf through bpf_program__set_prep(), and will be
 272  *   called before program is loaded. The processor should adjust
 273  *   the program one time for each instance according to the instance id
 274  *   passed to it.
 275  *
 276  * - bpf_program__set_prep:
 277  *   Attaches a preprocessor to a BPF program. The number of instances
 278  *   that should be created is also passed through this function.
 279  *
 280  * - bpf_program__nth_fd:
 281  *   After the program is loaded, get resulting FD of a given instance
 282  *   of the BPF program.
 283  *
 284  * If bpf_program__set_prep() is not used, the program would be loaded
 285  * without adjustment during bpf_object__load(). The program has only
 286  * one instance. In this case bpf_program__fd(prog) is equal to
 287  * bpf_program__nth_fd(prog, 0).
 288  */
 289
 290 struct bpf_prog_prep_result {
 291         /*
 292          * If not NULL, load new instruction array.
 293          * If set to NULL, don't load this instance.
 294          */
 295         struct bpf_insn *new_insn_ptr;
 296         int new_insn_cnt;
 297
 298         /* If not NULL, result FD is written to it. */
 299         int *pfd;
 300 };
 301
 302 /*
 303  * Parameters of bpf_program_prep_t:
 304  *  - prog:     The bpf_program being loaded.
 305  *  - n:        Index of instance being generated.
 306  *  - insns:    BPF instructions array.
 307  *  - insns_cnt:Number of instructions in insns.
 308  *  - res:      Output parameter, result of transformation.
 309  *
 310  * Return value:
 311  *  - Zero:     pre-processing success.
 312  *  - Non-zero: pre-processing error, stop loading.
 313  */
 314 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
 315                                   struct bpf_insn *insns, int insns_cnt,
 316                                   struct bpf_prog_prep_result *res);
 317
 318 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
 319                                      bpf_program_prep_t prep);
 320
 321 LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
 322
 323 /*
 324  * Adjust type of BPF program. Default is kprobe.
 325  */
 326 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
 327 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
 328 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
 329 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
 330 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
 331 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
 332 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
 333 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
 334 LIBBPF_API int bpf_program__set_tracing(struct bpf_program *prog);
 335
 336 LIBBPF_API enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog);
 337 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
 338                                       enum bpf_prog_type type);
 339
 340 LIBBPF_API enum bpf_attach_type
 341 bpf_program__get_expected_attach_type(struct bpf_program *prog);
 342 LIBBPF_API void
 343 bpf_program__set_expected_attach_type(struct bpf_program *prog,
 344                                       enum bpf_attach_type type);
 345
 346 LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
 347 LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
 348 LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
 349 LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
 350 LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
 351 LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
 352 LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
 353 LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
 354 LIBBPF_API bool bpf_program__is_tracing(const struct bpf_program *prog);
 355
 356 /*
 357  * No need for __attribute__((packed)), all members of 'bpf_map_def'
 358  * are all aligned.  In addition, using __attribute__((packed))
 359  * would trigger a -Wpacked warning message, and lead to an error
 360  * if -Werror is set.
 361  */
 362 struct bpf_map_def {
 363         unsigned int type;
 364         unsigned int key_size;
 365         unsigned int value_size;
 366         unsigned int max_entries;
 367         unsigned int map_flags;
 368 };
 369
 370 /*
 371  * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
 372  * so no need to worry about a name clash.
 373  */
 374 struct bpf_map;
 375 LIBBPF_API struct bpf_map *
 376 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
 377
 378 LIBBPF_API int
 379 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
 380
 381 /*
 382  * Get bpf_map through the offset of corresponding struct bpf_map_def
 383  * in the BPF object file.
 384  */
 385 LIBBPF_API struct bpf_map *
 386 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
 387
 388 LIBBPF_API struct bpf_map *
 389 bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
 390 #define bpf_object__for_each_map(pos, obj)              \
 391         for ((pos) = bpf_map__next(NULL, (obj));        \
 392              (pos) != NULL;                             \
 393              (pos) = bpf_map__next((pos), (obj)))
 394 #define bpf_map__for_each bpf_object__for_each_map
 395
 396 LIBBPF_API struct bpf_map *
 397 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
 398
 399 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
 400 LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
 401 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
 402 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
 403 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
 404
 405 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
 406 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
 407                                  bpf_map_clear_priv_t clear_priv);
 408 LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
 409 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 410 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
 411 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
 412 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 413 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
 414 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
 415 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
 416 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
 417 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
 418 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 419
 420 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 421
 422 LIBBPF_API long libbpf_get_error(const void *ptr);
 423
 424 struct bpf_prog_load_attr {
 425         const char *file;
 426         enum bpf_prog_type prog_type;
 427         enum bpf_attach_type expected_attach_type;
 428         int ifindex;
 429         int log_level;
 430         int prog_flags;
 431 };
 432
 433 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
 434                                    struct bpf_object **pobj, int *prog_fd);
 435 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
 436                              struct bpf_object **pobj, int *prog_fd);
 437
 438 struct xdp_link_info {
 439         __u32 prog_id;
 440         __u32 drv_prog_id;
 441         __u32 hw_prog_id;
 442         __u32 skb_prog_id;
 443         __u8 attach_mode;
 444 };
 445
 446 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
 447 LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
 448 LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
 449                                      size_t info_size, __u32 flags);
 450
 451 struct perf_buffer;
 452
 453 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
 454                                       void *data, __u32 size);
 455 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
 456
 457 /* common use perf buffer options */
 458 struct perf_buffer_opts {
 459         /* if specified, sample_cb is called for each sample */
 460         perf_buffer_sample_fn sample_cb;
 461         /* if specified, lost_cb is called for each batch of lost samples */
 462         perf_buffer_lost_fn lost_cb;
 463         /* ctx is provided to sample_cb and lost_cb */
 464         void *ctx;
 465 };
 466
 467 LIBBPF_API struct perf_buffer *
 468 perf_buffer__new(int map_fd, size_t page_cnt,
 469                  const struct perf_buffer_opts *opts);
 470
 471 enum bpf_perf_event_ret {
 472         LIBBPF_PERF_EVENT_DONE  = 0,
 473         LIBBPF_PERF_EVENT_ERROR = -1,
 474         LIBBPF_PERF_EVENT_CONT  = -2,
 475 };
 476
 477 struct perf_event_header;
 478
 479 typedef enum bpf_perf_event_ret
 480 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
 481
 482 /* raw perf buffer options, giving most power and control */
 483 struct perf_buffer_raw_opts {
 484         /* perf event attrs passed directly into perf_event_open() */
 485         struct perf_event_attr *attr;
 486         /* raw event callback */
 487         perf_buffer_event_fn event_cb;
 488         /* ctx is provided to event_cb */
 489         void *ctx;
 490         /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
 491          * max_entries of given PERF_EVENT_ARRAY map)
 492          */
 493         int cpu_cnt;
 494         /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
 495         int *cpus;
 496         /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
 497         int *map_keys;
 498 };
 499
 500 LIBBPF_API struct perf_buffer *
 501 perf_buffer__new_raw(int map_fd, size_t page_cnt,
 502                      const struct perf_buffer_raw_opts *opts);
 503
 504 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
 505 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
 506
 507 typedef enum bpf_perf_event_ret
 508         (*bpf_perf_event_print_t)(struct perf_event_header *hdr,
 509                                   void *private_data);
 510 LIBBPF_API enum bpf_perf_event_ret
 511 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
 512                            void **copy_mem, size_t *copy_size,
 513                            bpf_perf_event_print_t fn, void *private_data);
 514
 515 struct nlattr;
 516 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
 517 int libbpf_netlink_open(unsigned int *nl_pid);
 518 int libbpf_nl_get_link(int sock, unsigned int nl_pid,
 519                        libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
 520 int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
 521                         libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
 522 int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
 523                         libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
 524 int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
 525                          libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
 526
 527 struct bpf_prog_linfo;
 528 struct bpf_prog_info;
 529
 530 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
 531 LIBBPF_API struct bpf_prog_linfo *
 532 bpf_prog_linfo__new(const struct bpf_prog_info *info);
 533 LIBBPF_API const struct bpf_line_info *
 534 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
 535                                 __u64 addr, __u32 func_idx, __u32 nr_skip);
 536 LIBBPF_API const struct bpf_line_info *
 537 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
 538                       __u32 insn_off, __u32 nr_skip);
 539
 540 /*
 541  * Probe for supported system features
 542  *
 543  * Note that running many of these probes in a short amount of time can cause
 544  * the kernel to reach the maximal size of lockable memory allowed for the
 545  * user, causing subsequent probes to fail. In this case, the caller may want
 546  * to adjust that limit with setrlimit().
 547  */
 548 LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
 549                                     __u32 ifindex);
 550 LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
 551 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
 552                                  enum bpf_prog_type prog_type, __u32 ifindex);
 553
 554 /*
 555  * Get bpf_prog_info in continuous memory
 556  *
 557  * struct bpf_prog_info has multiple arrays. The user has option to choose
 558  * arrays to fetch from kernel. The following APIs provide an uniform way to
 559  * fetch these data. All arrays in bpf_prog_info are stored in a single
 560  * continuous memory region. This makes it easy to store the info in a
 561  * file.
 562  *
 563  * Before writing bpf_prog_info_linear to files, it is necessary to
 564  * translate pointers in bpf_prog_info to offsets. Helper functions
 565  * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
 566  * are introduced to switch between pointers and offsets.
 567  *
 568  * Examples:
 569  *   # To fetch map_ids and prog_tags:
 570  *   __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
 571  *           (1UL << BPF_PROG_INFO_PROG_TAGS);
 572  *   struct bpf_prog_info_linear *info_linear =
 573  *           bpf_program__get_prog_info_linear(fd, arrays);
 574  *
 575  *   # To save data in file
 576  *   bpf_program__bpil_addr_to_offs(info_linear);
 577  *   write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
 578  *
 579  *   # To read data from file
 580  *   read(f, info_linear, <proper_size>);
 581  *   bpf_program__bpil_offs_to_addr(info_linear);
 582  */
 583 enum bpf_prog_info_array {
 584         BPF_PROG_INFO_FIRST_ARRAY = 0,
 585         BPF_PROG_INFO_JITED_INSNS = 0,
 586         BPF_PROG_INFO_XLATED_INSNS,
 587         BPF_PROG_INFO_MAP_IDS,
 588         BPF_PROG_INFO_JITED_KSYMS,
 589         BPF_PROG_INFO_JITED_FUNC_LENS,
 590         BPF_PROG_INFO_FUNC_INFO,
 591         BPF_PROG_INFO_LINE_INFO,
 592         BPF_PROG_INFO_JITED_LINE_INFO,
 593         BPF_PROG_INFO_PROG_TAGS,
 594         BPF_PROG_INFO_LAST_ARRAY,
 595 };
 596
 597 struct bpf_prog_info_linear {
 598         /* size of struct bpf_prog_info, when the tool is compiled */
 599         __u32                   info_len;
 600         /* total bytes allocated for data, round up to 8 bytes */
 601         __u32                   data_len;
 602         /* which arrays are included in data */
 603         __u64                   arrays;
 604         struct bpf_prog_info    info;
 605         __u8                    data[];
 606 };
 607
 608 LIBBPF_API struct bpf_prog_info_linear *
 609 bpf_program__get_prog_info_linear(int fd, __u64 arrays);
 610
 611 LIBBPF_API void
 612 bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
 613
 614 LIBBPF_API void
 615 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
 616
 617 /*
 618  * A helper function to get the number of possible CPUs before looking up
 619  * per-CPU maps. Negative errno is returned on failure.
 620  *
 621  * Example usage:
 622  *
 623  *     int ncpus = libbpf_num_possible_cpus();
 624  *     if (ncpus < 0) {
 625  *          // error handling
 626  *     }
 627  *     long values[ncpus];
 628  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
 629  *
 630  */
 631 LIBBPF_API int libbpf_num_possible_cpus(void);
 632
 633 #ifdef __cplusplus
 634 } /* extern "C" */
 635 #endif
 636
 637 #endif /* __LIBBPF_LIBBPF_H */