1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3 /*
4 * Libbpf legacy APIs (either discouraged or deprecated, as mentioned in [0])
5 *
6 * [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY
7 *
8 * Copyright (C) 2021 Facebook
9 */
10 #ifndef __LIBBPF_LEGACY_BPF_H
11 #define __LIBBPF_LEGACY_BPF_H
12
13 #include <linux/bpf.h>
14 #include <stdbool.h>
15 #include <stddef.h>
16 #include <stdint.h>
17 #include "libbpf_common.h"
18
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22
23 /* As of libbpf 1.0 libbpf_set_strict_mode() and enum libbpf_struct_mode have
24 * no effect. But they are left in libbpf_legacy.h so that applications that
25 * prepared for libbpf 1.0 before final release by using
26 * libbpf_set_strict_mode() still work with libbpf 1.0+ without any changes.
27 */
28 enum libbpf_strict_mode {
29 /* Turn on all supported strict features of libbpf to simulate libbpf
30 * v1.0 behavior.
31 * This will be the default behavior in libbpf v1.0.
32 */
33 LIBBPF_STRICT_ALL = 0xffffffff,
34
35 /*
36 * Disable any libbpf 1.0 behaviors. This is the default before libbpf
37 * v1.0. It won't be supported anymore in v1.0, please update your
38 * code so that it handles LIBBPF_STRICT_ALL mode before libbpf v1.0.
39 */
40 LIBBPF_STRICT_NONE = 0x00,
41 /*
42 * Return NULL pointers on error, not ERR_PTR(err).
43 * Additionally, libbpf also always sets errno to corresponding Exx
44 * (positive) error code.
45 */
46 LIBBPF_STRICT_CLEAN_PTRS = 0x01,
47 /*
48 * Return actual error codes from low-level APIs directly, not just -1.
49 * Additionally, libbpf also always sets errno to corresponding Exx
50 * (positive) error code.
51 */
52 LIBBPF_STRICT_DIRECT_ERRS = 0x02,
53 /*
54 * Enforce strict BPF program section (SEC()) names.
55 * E.g., while prefiously SEC("xdp_whatever") or SEC("perf_event_blah") were
56 * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
57 * unrecognized by libbpf and would have to be just SEC("xdp") and
58 * SEC("xdp") and SEC("perf_event").
59 *
60 * Note, in this mode the program pin path will be based on the
61 * function name instead of section name.
62 *
63 * Additionally, routines in the .text section are always considered
64 * sub-programs. Legacy behavior allows for a single routine in .text
65 * to be a program.
66 */
67 LIBBPF_STRICT_SEC_NAME = 0x04,
68 /*
69 * Disable the global 'bpf_objects_list'. Maintaining this list adds
70 * a race condition to bpf_object__open() and bpf_object__close().
71 * Clients can maintain it on their own if it is valuable for them.
72 */
73 LIBBPF_STRICT_NO_OBJECT_LIST = 0x08,
74 /*
75 * Automatically bump RLIMIT_MEMLOCK using setrlimit() before the
76 * first BPF program or map creation operation. This is done only if
77 * kernel is too old to support memcg-based memory accounting for BPF
78 * subsystem. By default, RLIMIT_MEMLOCK limit is set to RLIM_INFINITY,
79 * but it can be overriden with libbpf_set_memlock_rlim() API.
80 * Note that libbpf_set_memlock_rlim() needs to be called before
81 * the very first bpf_prog_load(), bpf_map_create() or bpf_object__load()
82 * operation.
83 */
84 LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK = 0x10,
85 /*
86 * Error out on any SEC("maps") map definition, which are deprecated
87 * in favor of BTF-defined map definitions in SEC(".maps").
88 */
89 LIBBPF_STRICT_MAP_DEFINITIONS = 0x20,
90
91 __LIBBPF_STRICT_LAST,
92 };
93
94 LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode);
95
96 /**
97 * @brief **libbpf_get_error()** extracts the error code from the passed
98 * pointer
99 * @param ptr pointer returned from libbpf API function
100 * @return error code; or 0 if no error occured
101 *
102 * Note, as of libbpf 1.0 this function is not necessary and not recommended
103 * to be used. Libbpf doesn't return error code embedded into the pointer
104 * itself. Instead, NULL is returned on error and error code is passed through
105 * thread-local errno variable. **libbpf_get_error()** is just returning -errno
106 * value if it receives NULL, which is correct only if errno hasn't been
107 * modified between libbpf API call and corresponding **libbpf_get_error()**
108 * call. Prefer to check return for NULL and use errno directly.
109 *
110 * This API is left in libbpf 1.0 to allow applications that were 1.0-ready
111 * before final libbpf 1.0 without needing to change them.
112 */
113 LIBBPF_API long libbpf_get_error(const void *ptr);
114
115 #define DECLARE_LIBBPF_OPTS LIBBPF_OPTS
116
117 /* "Discouraged" APIs which don't follow consistent libbpf naming patterns.
118 * They are normally a trivial aliases or wrappers for proper APIs and are
119 * left to minimize unnecessary disruption for users of libbpf. But they
120 * shouldn't be used going forward.
121 */
122
123 struct bpf_program;
124 struct bpf_map;
125 struct btf;
126 struct btf_ext;
127
128 LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
129
130 LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
131 LIBBPF_API enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
132 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
133 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
134 LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size);
135
136 #ifdef __cplusplus
137 } /* extern "C" */
138 #endif
139
140 #endif /* __LIBBPF_LEGACY_BPF_H */
141
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