| // 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 <string> |
| |
| #include "base/check_op.h" |
| #include "base/functional/function_ref.h" |
| #include "base/numerics/safe_conversions.h" |
| #include "build/build_config.h" |
| #include "third_party/abseil-cpp/absl/types/optional.h" |
| |
| namespace { |
| |
| absl::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 absl::nullopt; |
| } |
| |
| std::string value(buf_len - 1, '\0'); |
| result = sysctl_func(&value[0], &buf_len); |
| if (result < 0) { |
| return absl::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 { |
| |
| absl::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) |
| absl::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 |