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
 20extern "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 */
 28enum 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
 94LIBBPF_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 */
113LIBBPF_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
123struct bpf_program;
124struct bpf_map;
125struct btf;
126struct btf_ext;
127
128LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
129
130LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
131LIBBPF_API enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog);
132LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
133LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
134LIBBPF_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 */