Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

Sources/OpenVPN3/openvpn/log/logthread.hpp

@@ -0,0 +1,168 @@
+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program 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 Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+// This is a general-purpose logging framework that allows for OPENVPN_LOG and
+// OPENVPN_LOG_NTNL macros to dispatch logging data to a thread-local handler.
+
+// NOTE: define USE_ASIO_THREADLOCAL if your C++ doesn't support the
+// "thread_local" attribute.
+
+#ifndef OPENVPN_LOG_LOGTHREAD_H
+#define OPENVPN_LOG_LOGTHREAD_H
+
+#include <string>
+#include <sstream>
+#include <thread>
+
+#if defined(USE_ASIO) && defined(USE_ASIO_THREADLOCAL)
+#include <asio/detail/tss_ptr.hpp>
+#endif
+
+#include <openvpn/common/size.hpp>
+#include <openvpn/common/extern.hpp>
+
+// Define these parameters before including this header:
+
+// OPENVPN_LOG_CLASS -- client class that exposes a log() method
+// OPENVPN_LOG_INFO  -- converts a log string to the form that should be passed to log()
+
+#ifndef OPENVPN_LOG_CLASS
+#error OPENVPN_LOG_CLASS must be defined
+#endif
+
+#ifndef OPENVPN_LOG_INFO
+#error OPENVPN_LOG_INFO must be defined
+#endif
+
+# define OPENVPN_LOG(args) \
+  do { \
+    if (openvpn::Log::Context::defined()) {	\
+      std::ostringstream _ovpn_log; \
+      _ovpn_log << args << '\n'; \
+      (openvpn::Log::Context::obj()->log(OPENVPN_LOG_INFO(_ovpn_log.str()))); \
+    } \
+  } while (0)
+
+// like OPENVPN_LOG but no trailing newline
+#define OPENVPN_LOG_NTNL(args) \
+  do { \
+    if (openvpn::Log::Context::defined()) {	\
+      std::ostringstream _ovpn_log; \
+      _ovpn_log << args; \
+      (openvpn::Log::Context::obj()->log(OPENVPN_LOG_INFO(_ovpn_log.str()))); \
+    } \
+  } while (0)
+
+# define OPENVPN_LOG_STRING(str) \
+  do { \
+    if (openvpn::Log::Context::defined()) {			  \
+      (openvpn::Log::Context::obj()->log(OPENVPN_LOG_INFO(str))); \
+    } \
+  } while (0)
+
+namespace openvpn {
+  namespace Log {
+
+#ifdef OPENVPN_LOG_GLOBAL
+    // OPENVPN_LOG uses global object pointer
+    OPENVPN_EXTERN OPENVPN_LOG_CLASS* global_log; // GLOBAL
+    struct Context
+    {
+      struct Wrapper
+      {
+      };
+
+      Context(const Wrapper& wrap)
+      {
+      }
+
+      Context(OPENVPN_LOG_CLASS *cli)
+      {
+	global_log = cli;
+      }
+
+      ~Context()
+      {
+	global_log = nullptr;
+      }
+
+      static bool defined()
+      {
+	return global_log != nullptr;
+      }
+
+      static OPENVPN_LOG_CLASS* obj()
+      {
+	return global_log;
+      }
+    };
+#else
+    // OPENVPN_LOG uses thread-local object pointer
+#if defined(USE_ASIO) && defined(USE_ASIO_THREADLOCAL)
+    OPENVPN_EXTERN asio::detail::tss_ptr<OPENVPN_LOG_CLASS> global_log; // GLOBAL
+#else
+    OPENVPN_EXTERN thread_local OPENVPN_LOG_CLASS* global_log; // GLOBAL
+#endif
+    struct Context
+    {
+      // Mechanism for passing thread-local
+      // global_log to another thread.
+      class Wrapper
+      {
+      public:
+	Wrapper() : log(obj()) {}
+      private:
+	friend struct Context;
+	OPENVPN_LOG_CLASS *log;
+      };
+
+      // While in scope, turns on global_log
+      // for this thread.
+      Context(const Wrapper& wrap)
+      {
+	global_log = wrap.log;
+      }
+
+      Context(OPENVPN_LOG_CLASS *cli)
+      {
+	global_log = cli;
+      }
+
+      ~Context()
+      {
+	global_log = nullptr;
+      }
+
+      static bool defined()
+      {
+	return global_log != nullptr;
+      }
+
+      static OPENVPN_LOG_CLASS* obj()
+      {
+	return global_log;
+      }
+    };
+#endif
+  }
+}
+
+#endif