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

Sources/OpenVPN3/openvpn/asio/scoped_asio_stream.hpp

@@ -0,0 +1,108 @@
+//    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/>.
+
+// A scoped Asio stream that is automatically closed by its destructor.
+
+#ifndef OPENVPN_ASIO_SCOPED_ASIO_STREAM_H
+#define OPENVPN_ASIO_SCOPED_ASIO_STREAM_H
+
+#include <openvpn/common/size.hpp>
+
+namespace openvpn {
+
+  template <typename STREAM>
+  class ScopedAsioStream
+  {
+    ScopedAsioStream(const ScopedAsioStream&) = delete;
+    ScopedAsioStream& operator=(const ScopedAsioStream&) = delete;
+
+  public:
+    typedef STREAM* base_type;
+
+    ScopedAsioStream() : obj_(undefined()) {}
+
+    explicit ScopedAsioStream(STREAM *obj)
+      : obj_(obj) {}
+
+    static STREAM* undefined() { return nullptr; }
+
+    STREAM* release()
+    {
+      STREAM* ret = obj_;
+      obj_ = nullptr;
+      //OPENVPN_LOG("**** SAS RELEASE=" << ret);
+      return ret;
+    }
+
+    static bool defined_static(STREAM* obj)
+    {
+      return obj != nullptr;
+    }
+
+    bool defined() const
+    {
+      return defined_static(obj_);
+    }
+
+    STREAM* operator()() const
+    {
+      return obj_;
+    }
+
+    void reset(STREAM* obj)
+    {
+      close();
+      obj_ = obj;
+      //OPENVPN_LOG("**** SAS RESET=" << obj_);
+    }
+
+    // unusual semantics: replace obj without closing it first
+    void replace(STREAM* obj)
+    {
+      //OPENVPN_LOG("**** SAS REPLACE " << obj_ << " -> " << obj);
+      obj_ = obj;
+    }
+
+    // return false if close error
+    bool close()
+    {
+      if (defined())
+	{
+	  //OPENVPN_LOG("**** SAS CLOSE obj=" << obj_);
+	  delete obj_;
+	  obj_ = nullptr;
+	}
+      return true;
+    }
+
+    ~ScopedAsioStream()
+    {
+      //OPENVPN_LOG("**** SAS DESTRUCTOR");
+      close();
+    }
+
+  private:
+    STREAM* obj_;
+  };
+
+} // namespace openvpn
+
+#endif