| /* |
| * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "iphlp_interface.hpp" |
| #include "runtime/os.hpp" |
| |
| // IPHLP API |
| typedef DWORD(WINAPI *GetIfTable2_Fn)(PMIB_IF_TABLE2*); |
| typedef DWORD(WINAPI *FreeMibTable_Fn)(PVOID); |
| |
| // IPHLP statics |
| GetIfTable2_Fn IphlpDll::_GetIfTable2 = NULL; |
| FreeMibTable_Fn IphlpDll::_FreeMibTable = NULL; |
| |
| LONG IphlpDll::_critical_section = 0; |
| LONG IphlpDll::_initialized = 0; |
| LONG IphlpDll::_iphlp_reference_count = 0; |
| HMODULE IphlpDll::_hModule = NULL; |
| |
| void IphlpDll::initialize(void) { |
| _hModule = os::win32::load_Windows_dll("iphlpapi.dll", NULL, 0); |
| |
| if (NULL == _hModule) { |
| return; |
| } |
| |
| // The 'A' at the end means the ANSI (not the UNICODE) vesions of the methods |
| _GetIfTable2 = (GetIfTable2_Fn)::GetProcAddress(_hModule, "GetIfTable2"); |
| _FreeMibTable = (FreeMibTable_Fn)::GetProcAddress(_hModule, "FreeMibTable"); |
| |
| // interlock is used for fencing |
| InterlockedExchange(&_initialized, 1); |
| } |
| |
| bool IphlpDll::IphlpDetach(void) { |
| LONG prev_ref_count = InterlockedExchangeAdd(&_iphlp_reference_count, -1); |
| BOOL ret = false; |
| |
| if (1 == prev_ref_count) { |
| if (_initialized && _hModule != NULL) { |
| ret = FreeLibrary(_hModule); |
| if (ret) { |
| _hModule = NULL; |
| _GetIfTable2 = NULL; |
| _FreeMibTable = NULL; |
| InterlockedExchange(&_initialized, 0); |
| } |
| } |
| } |
| return ret != 0; |
| } |
| |
| bool IphlpDll::IphlpAttach(void) { |
| InterlockedExchangeAdd(&_iphlp_reference_count, 1); |
| |
| if (1 == _initialized) { |
| return true; |
| } |
| |
| while (InterlockedCompareExchange(&_critical_section, 1, 0) == 1); |
| |
| if (0 == _initialized) { |
| initialize(); |
| } |
| |
| while (InterlockedCompareExchange(&_critical_section, 0, 1) == 0); |
| |
| return (_GetIfTable2 != NULL && _FreeMibTable != NULL); |
| } |
| |
| DWORD IphlpDll::GetIfTable2(PMIB_IF_TABLE2* Table) { |
| assert(_initialized && _GetIfTable2 != NULL, |
| "IphlpAttach() not yet called"); |
| |
| return _GetIfTable2(Table); |
| } |
| |
| DWORD IphlpDll::FreeMibTable(PVOID Memory) { |
| assert(_initialized && _FreeMibTable != NULL, |
| "IphlpAttach() not yet called"); |
| |
| return _FreeMibTable(Memory); |
| } |