move LoadLibrary logic to new win_util module (#1464)

move LoadLibrary logic to new win_util module. use get_library_procedure as common windows dyn proc load routine

include/libtorrent/Makefile.am

@@ -184,6 +184,7 @@ nobase_include_HEADERS = \
   aux_/has_block.hpp                \
   aux_/scope_end.hpp                \
   aux_/vector.hpp                   \
+  aux_/win_util.hpp                 \
   \
   extensions/smart_ban.hpp          \
   extensions/ut_metadata.hpp        \

include/libtorrent/aux_/win_util.hpp

@@ -0,0 +1,85 @@
+/*
+
+Copyright (c) 2016, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_WIN_UTIL_HPP
+#define TORRENT_WIN_UTIL_HPP
+
+#include "libtorrent/config.hpp"
+
+namespace libtorrent { namespace aux
+{
+	template <typename Library>
+	HMODULE get_library_handle()
+	{
+		static bool handle_checked = false;
+		static HMODULE handle = 0;
+
+		if (!handle_checked)
+		{
+			handle = LoadLibraryA(Library::library_name);
+			handle_checked = true;
+		}
+		return handle;
+	}
+
+	template <typename Library, typename Signature>
+	Signature get_library_procedure(LPCSTR name)
+	{
+		static Signature proc = nullptr;
+		static bool failed_proc = false;
+
+		if ((proc == nullptr) && !failed_proc)
+		{
+			HMODULE const handle = get_library_handle<Library>();
+			if (handle) proc = (Signature)GetProcAddress(handle, name);
+			failed_proc = (proc == nullptr);
+		}
+		return proc;
+	}
+
+	struct iphlpapi {
+		static constexpr char const* library_name = "iphlpapi.dll";
+	};
+
+	struct kernel32 {
+		static constexpr char const* library_name = "kernel32.dll";
+	};
+
+	struct advapi32 {
+		static constexpr char const* library_name = "advapi32.dll";
+	};
+
+} // namespace aux
+} // namespace libtorrent
+
+#endif
+

src/enum_net.cpp

@@ -35,6 +35,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/broadcast_socket.hpp"
 #include "libtorrent/assert.hpp"
 #include "libtorrent/socket_type.hpp"
+#ifdef TORRENT_WINDOWS
+#include "libtorrent/aux_/win_util.hpp"
+#endif
 
 #include <functional>
 #include <cstdlib> // for wcstombscstombs
@@ -385,41 +388,6 @@ namespace libtorrent
 		return false;
 	}
 
-#ifdef TORRENT_WINDOWS
-	struct iphlpapi {
-		static constexpr char const* library_name = "iphlpapi.dll";
-	};
-
-	template <typename Library>
-	HMODULE get_library_handle()
-	{
-		static bool handle_checked = false;
-		static HMODULE handle = 0;
-
-		if (!handle_checked)
-		{
-			handle = LoadLibraryA(Library::library_name);
-			handle_checked = true;
-		}
-		return handle;
-	}
-
-	template <typename Library, typename Signature>
-	Signature get_library_procedure(LPCSTR name)
-	{
-		static Signature proc = nullptr;
-		static bool failed_proc = false;
-
-		if ((proc == nullptr) && !failed_proc)
-		{
-			HMODULE const handle = get_library_handle<Library>();
-			if (handle) proc = (Signature)GetProcAddress(handle, name);
-			failed_proc = (proc == nullptr);
-		}
-		return proc;
-	}
-#endif
-
 #if TORRENT_USE_GETIPFORWARDTABLE
 	address build_netmask(int bits, int family)
 	{
@@ -628,7 +596,7 @@ namespace libtorrent
 		typedef ULONG (WINAPI *GetAdaptersAddresses_t)(ULONG,ULONG,PVOID,PIP_ADAPTER_ADDRESSES,PULONG);
 		// Get GetAdaptersAddresses() pointer
 		auto GetAdaptersAddresses =
-			get_library_procedure<iphlpapi, GetAdaptersAddresses_t>("GetAdaptersAddresses");
+			aux::get_library_procedure<aux::iphlpapi, GetAdaptersAddresses_t>("GetAdaptersAddresses");
 
 		if (GetAdaptersAddresses != nullptr)
 		{
@@ -988,7 +956,7 @@ namespace libtorrent
 */
 
 		typedef DWORD (WINAPI *GetIfEntry_t)(PMIB_IFROW pIfRow);
-		auto GetIfEntry = get_library_procedure<iphlpapi, GetIfEntry_t>("GetIfEntry");
+		auto GetIfEntry = aux::get_library_procedure<aux::iphlpapi, GetIfEntry_t>("GetIfEntry");
 
 		if (GetIfEntry == nullptr)
 		{
@@ -1001,8 +969,8 @@ namespace libtorrent
 			ADDRESS_FAMILY, PMIB_IPFORWARD_TABLE2*);
 		typedef void (WINAPI *FreeMibTable_t)(PVOID Memory);
 
-		auto GetIpForwardTable2 = get_library_procedure<iphlpapi, GetIpForwardTable2_t>("GetIpForwardTable2");
+		auto GetIpForwardTable2 = aux::get_library_procedure<aux::iphlpapi, GetIpForwardTable2_t>("GetIpForwardTable2");
-		auto FreeMibTable = get_library_procedure<iphlpapi, FreeMibTable_t>("FreeMibTable");
+		auto FreeMibTable = aux::get_library_procedure<aux::iphlpapi, FreeMibTable_t>("FreeMibTable");
 		if (GetIpForwardTable2 != nullptr && FreeMibTable != nullptr)
 		{
 			MIB_IPFORWARD_TABLE2* routes = nullptr;
@@ -1035,7 +1003,7 @@ namespace libtorrent
 		// Get GetIpForwardTable() pointer
 		typedef DWORD (WINAPI *GetIpForwardTable_t)(PMIB_IPFORWARDTABLE pIpForwardTable,PULONG pdwSize,BOOL bOrder);
 
-		auto GetIpForwardTable = get_library_procedure<iphlpapi, GetIpForwardTable_t>("GetIpForwardTable");
+		auto GetIpForwardTable = aux::get_library_procedure<aux::iphlpapi, GetIpForwardTable_t>("GetIpForwardTable");
 		if (GetIpForwardTable == nullptr)
 		{
 			ec = boost::asio::error::operation_not_supported;

src/file.cpp

@@ -99,6 +99,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 #include "libtorrent/utf8.hpp"
+#include "libtorrent/aux_/win_util.hpp"
 
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
@@ -1976,38 +1977,23 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 			PTOKEN_PRIVILEGES PreviousState,
 			PDWORD ReturnLength);
 
-		static OpenProcessToken_t pOpenProcessToken = nullptr;
+		auto OpenProcessToken =
-		static LookupPrivilegeValue_t pLookupPrivilegeValue = nullptr;
+			aux::get_library_procedure<aux::advapi32, OpenProcessToken_t>("OpenProcessToken");
-		static AdjustTokenPrivileges_t pAdjustTokenPrivileges = nullptr;
+		auto LookupPrivilegeValue =
-		static bool failed_advapi = false;
+			aux::get_library_procedure<aux::advapi32, LookupPrivilegeValue_t>("LookupPrivilegeValueA");
+		auto AdjustTokenPrivileges =
+			aux::get_library_procedure<aux::advapi32, AdjustTokenPrivileges_t>("AdjustTokenPrivileges");
+
+		if (OpenProcessToken == nullptr || LookupPrivilegeValue == nullptr || AdjustTokenPrivileges == nullptr) return false;
 
-		if (pOpenProcessToken == nullptr && !failed_advapi)
-		{
-			HMODULE advapi = LoadLibraryA("advapi32");
-			if (advapi == nullptr)
-			{
-				failed_advapi = true;
-				return false;
-			}
-			pOpenProcessToken = (OpenProcessToken_t)GetProcAddress(advapi, "OpenProcessToken");
-			pLookupPrivilegeValue = (LookupPrivilegeValue_t)GetProcAddress(advapi, "LookupPrivilegeValueA");
-			pAdjustTokenPrivileges = (AdjustTokenPrivileges_t)GetProcAddress(advapi, "AdjustTokenPrivileges");
-			if (pOpenProcessToken == nullptr
-				|| pLookupPrivilegeValue == nullptr
-				|| pAdjustTokenPrivileges == nullptr)
-			{
-				failed_advapi = true;
-				return false;
-			}
-		}
 
 		HANDLE token;
-		if (!pOpenProcessToken(GetCurrentProcess()
+		if (!OpenProcessToken(GetCurrentProcess()
 			, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &token))
 			return false;
 
 		TOKEN_PRIVILEGES privs;
-		if (!pLookupPrivilegeValue(nullptr, "SeManageVolumePrivilege"
+		if (!LookupPrivilegeValue(nullptr, "SeManageVolumePrivilege"
 			, &privs.Privileges[0].Luid))
 		{
 			CloseHandle(token);
@@ -2017,7 +2003,7 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 		privs.PrivilegeCount = 1;
 		privs.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
 
-		bool ret = pAdjustTokenPrivileges(token, FALSE, &privs, 0, nullptr, nullptr)
+		bool ret = AdjustTokenPrivileges(token, FALSE, &privs, 0, nullptr, nullptr)
 			&& GetLastError() == ERROR_SUCCESS;
 
 		CloseHandle(token);
@@ -2028,30 +2014,14 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 	void set_file_valid_data(HANDLE f, std::int64_t size)
 	{
 		typedef BOOL (WINAPI *SetFileValidData_t)(HANDLE, LONGLONG);
-		static SetFileValidData_t pSetFileValidData = nullptr;
+		auto SetFileValidData =
-		static bool failed_kernel32 = false;
+			aux::get_library_procedure<aux::kernel32, SetFileValidData_t>("SetFileValidData");
 
-		if (pSetFileValidData == nullptr && !failed_kernel32)
+		if (SetFileValidData == nullptr) return;
-		{
-			HMODULE k32 = LoadLibraryA("kernel32");
-			if (k32 == nullptr)
-			{
-				failed_kernel32 = true;
-				return;
-			}
-			pSetFileValidData = (SetFileValidData_t)GetProcAddress(k32, "SetFileValidData");
-			if (pSetFileValidData == nullptr)
-			{
-				failed_kernel32 = true;
-				return;
-			}
-		}
-
-		TORRENT_ASSERT(pSetFileValidData);
 
 		// we don't necessarily expect to have enough
 		// privilege to do this, so ignore errors.
-		pSetFileValidData(f, size);
+		SetFileValidData(f, size);
 	}
 #endif
 
@@ -2095,30 +2065,16 @@ typedef struct _FILE_ALLOCATED_RANGE_BUFFER {
 				, LPVOID lpFileInformation
 				, DWORD dwBufferSize);
 
-			static GetFileInformationByHandleEx_t GetFileInformationByHandleEx_ = nullptr;
+			auto GetFileInformationByHandleEx =
-
+				aux::get_library_procedure<aux::kernel32, GetFileInformationByHandleEx_t>("GetFileInformationByHandleEx");
-			static bool failed_kernel32 = false;
-
-			if ((GetFileInformationByHandleEx_ == nullptr) && !failed_kernel32)
-			{
-				HMODULE kernel32 = LoadLibraryA("kernel32.dll");
-				if (kernel32)
-				{
-					GetFileInformationByHandleEx_ = (GetFileInformationByHandleEx_t)GetProcAddress(kernel32, "GetFileInformationByHandleEx");
-				}
-				else
-				{
-					failed_kernel32 = true;
-				}
-			}
 
 			offs.QuadPart = 0;
-			if (GetFileInformationByHandleEx_)
+			if (GetFileInformationByHandleEx != nullptr)
 			{
 				// only allocate the space if the file
 				// is not fully allocated
 				FILE_STANDARD_INFO inf;
-				if (GetFileInformationByHandleEx_(native_handle()
+				if (GetFileInformationByHandleEx(native_handle()
 					, FileStandardInfo, &inf, sizeof(inf)) == FALSE)
 				{
 					ec.assign(GetLastError(), system_category());

src/file_pool.cpp

@@ -37,6 +37,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/error_code.hpp"
 #include "libtorrent/file_storage.hpp"
 #include "libtorrent/units.hpp"
+#ifdef TORRENT_WINDOWS
+#include "libtorrent/aux_/win_util.hpp"
+#endif
 
 #include <limits>
 
@@ -85,30 +88,10 @@ namespace libtorrent
 		} FILE_IO_PRIORITY_HINT_INFO_LOCAL;
 
 		typedef BOOL (WINAPI *SetFileInformationByHandle_t)(HANDLE hFile, FILE_INFO_BY_HANDLE_CLASS_LOCAL FileInformationClass, LPVOID lpFileInformation, DWORD dwBufferSize);
-		static SetFileInformationByHandle_t SetFileInformationByHandle = nullptr;
+		auto SetFileInformationByHandle =
+			aux::get_library_procedure<aux::kernel32, SetFileInformationByHandle_t>("SetFileInformationByHandle");
 
-		static bool failed_kernel_load = false;
+		if (SetFileInformationByHandle == nullptr) return;
-
-		if (failed_kernel_load) return;
-
-		if (SetFileInformationByHandle == nullptr)
-		{
-			HMODULE kernel32 = LoadLibraryA("kernel32.dll");
-			if (kernel32 == nullptr)
-			{
-				failed_kernel_load = true;
-				return;
-			}
-
-			SetFileInformationByHandle = (SetFileInformationByHandle_t)GetProcAddress(kernel32, "SetFileInformationByHandle");
-			if (SetFileInformationByHandle == nullptr)
-			{
-				failed_kernel_load = true;
-				return;
-			}
-		}
-
-		TORRENT_ASSERT(SetFileInformationByHandle);
 
 		FILE_IO_PRIORITY_HINT_INFO_LOCAL io_hint;
 		io_hint.PriorityHint = IoPriorityHintLow;