tools/lib/bpf/libbpf.h

   1 /*
   2  * Common eBPF ELF object loading operations.
   3  *
   4  * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
   5  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   6  * Copyright (C) 2015 Huawei Inc.
   7  */
   8 #ifndef __BPF_LIBBPF_H
   9 #define __BPF_LIBBPF_H
  10
  11 #include <stdio.h>
  12 #include <stdbool.h>
  13 #include <linux/err.h>
  14
  15 enum libbpf_errno {
  16         __LIBBPF_ERRNO__START = 4000,
  17
  18         /* Something wrong in libelf */
  19         LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
  20         LIBBPF_ERRNO__FORMAT,   /* BPF object format invalid */
  21         LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
  22         LIBBPF_ERRNO__ENDIAN,   /* Endian missmatch */
  23         LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
  24         LIBBPF_ERRNO__RELOC,    /* Relocation failed */
  25         LIBBPF_ERRNO__LOAD,     /* Load program failure for unknown reason */
  26         LIBBPF_ERRNO__VERIFY,   /* Kernel verifier blocks program loading */
  27         LIBBPF_ERRNO__PROG2BIG, /* Program too big */
  28         LIBBPF_ERRNO__KVER,     /* Incorrect kernel version */
  29         __LIBBPF_ERRNO__END,
  30 };
  31
  32 int libbpf_strerror(int err, char *buf, size_t size);
  33
  34 /*
  35  * In include/linux/compiler-gcc.h, __printf is defined. However
  36  * it should be better if libbpf.h doesn't depend on Linux header file.
  37  * So instead of __printf, here we use gcc attribute directly.
  38  */
  39 typedef int (*libbpf_print_fn_t)(const char *, ...)
  40         __attribute__((format(printf, 1, 2)));
  41
  42 void libbpf_set_print(libbpf_print_fn_t warn,
  43                       libbpf_print_fn_t info,
  44                       libbpf_print_fn_t debug);
  45
  46 /* Hide internal to user */
  47 struct bpf_object;
  48
  49 struct bpf_object *bpf_object__open(const char *path);
  50 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
  51                                            size_t obj_buf_sz,
  52                                            const char *name);
  53 void bpf_object__close(struct bpf_object *object);
  54
  55 /* Load/unload object into/from kernel */
  56 int bpf_object__load(struct bpf_object *obj);
  57 int bpf_object__unload(struct bpf_object *obj);
  58 const char *bpf_object__get_name(struct bpf_object *obj);
  59 unsigned int bpf_object__get_kversion(struct bpf_object *obj);
  60
  61 struct bpf_object *bpf_object__next(struct bpf_object *prev);
  62 #define bpf_object__for_each_safe(pos, tmp)                     \
  63         for ((pos) = bpf_object__next(NULL),            \
  64                 (tmp) = bpf_object__next(pos);          \
  65              (pos) != NULL;                             \
  66              (pos) = (tmp), (tmp) = bpf_object__next(tmp))
  67
  68 /* Accessors of bpf_program. */
  69 struct bpf_program;
  70 struct bpf_program *bpf_program__next(struct bpf_program *prog,
  71                                       struct bpf_object *obj);
  72
  73 #define bpf_object__for_each_program(pos, obj)          \
  74         for ((pos) = bpf_program__next(NULL, (obj));    \
  75              (pos) != NULL;                             \
  76              (pos) = bpf_program__next((pos), (obj)))
  77
  78 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
  79                                          void *);
  80
  81 int bpf_program__set_private(struct bpf_program *prog, void *priv,
  82                              bpf_program_clear_priv_t clear_priv);
  83
  84 int bpf_program__get_private(struct bpf_program *prog,
  85                              void **ppriv);
  86
  87 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
  88
  89 int bpf_program__fd(struct bpf_program *prog);
  90
  91 /*
  92  * We don't need __attribute__((packed)) now since it is
  93  * unnecessary for 'bpf_map_def' because they are all aligned.
  94  * In addition, using it will trigger -Wpacked warning message,
  95  * and will be treated as an error due to -Werror.
  96  */
  97 struct bpf_map_def {
  98         unsigned int type;
  99         unsigned int key_size;
 100         unsigned int value_size;
 101         unsigned int max_entries;
 102 };
 103
 104 #endif