xref: /openbmc/linux/tools/lib/bpf/libbpf.h (revision 6a613ac6)
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
105