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

Sources/OpenVPN3/openvpn/linux/daemon_alive.hpp

@@ -0,0 +1,59 @@
+//    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/>.
+
+#ifndef OPENVPN_LINUX_DAEMON_ALIVE_H
+#define OPENVPN_LINUX_DAEMON_ALIVE_H
+
+#include <openvpn/common/file.hpp>
+#include <openvpn/common/string.hpp>
+#include <openvpn/common/number.hpp>
+
+namespace openvpn {
+  inline int daemon_pid(const std::string& cmd,
+			const std::string& pidfile)
+  {
+    try {
+      std::string pidstr = read_text(pidfile);
+      string::trim_crlf(pidstr);
+      const std::string cmdline_fn = "/proc/" + pidstr + "/cmdline";
+      BufferPtr cmdbuf = read_binary_linear(cmdline_fn);
+      const size_t len = ::strnlen((const char *)cmdbuf->c_data(), cmdbuf->size());
+      if (cmd == std::string((const char *)cmdbuf->c_data(), len))
+	{
+	  int ret;
+	  if (parse_number(pidstr, ret))
+	    return ret;
+	}
+    }
+    catch (const std::exception& e)
+      {
+      }
+    return -1;
+  }
+
+  inline bool is_daemon_alive(const std::string& cmd,
+			      const std::string& pidfile)
+  {
+    return daemon_pid(cmd, pidfile) >= 0;
+  }
+}
+
+#endif