1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/posix/sysctl.h"
#include <sys/sysctl.h>
#include <initializer_list>
#include <optional>
#include <string>
#include "base/check_op.h"
#include "base/functional/function_ref.h"
#include "base/numerics/safe_conversions.h"
#include "build/build_config.h"
namespace {
std::optional<std::string> StringSysctlImpl(
base::FunctionRef<int(char* /*out*/, size_t* /*out_len*/)> sysctl_func) {
size_t buf_len;
int result = sysctl_func(nullptr, &buf_len);
if (result < 0 || buf_len < 1) {
return std::nullopt;
}
std::string value(buf_len - 1, '\0');
result = sysctl_func(&value[0], &buf_len);
if (result < 0) {
return std::nullopt;
}
CHECK_LE(buf_len - 1, value.size());
CHECK_EQ(value[buf_len - 1], '\0');
value.resize(buf_len - 1);
return value;
}
} // namespace
namespace base {
std::optional<std::string> StringSysctl(const std::initializer_list<int>& mib) {
return StringSysctlImpl([mib](char* out, size_t* out_len) {
return sysctl(const_cast<int*>(std::data(mib)),
checked_cast<unsigned int>(std::size(mib)), out, out_len,
nullptr, 0);
});
}
#if !BUILDFLAG(IS_OPENBSD)
std::optional<std::string> StringSysctlByName(const char* name) {
return StringSysctlImpl([name](char* out, size_t* out_len) {
return sysctlbyname(name, out, out_len, nullptr, 0);
});
}
#endif
} // namespace base
|
