Use interactice service to start openvpn process

Instead of starting openvpn process directly:

 - connect to interactive service pipe
 - send startup info
 - read openvpn process pid (for watchdog)

GitHub: #23

Signed-off-by: Lev Stipakov <[email protected]>

Author: lstipakov

OpenVPNChild.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.IO.Pipes;
 using System.Linq;
 using System.Text;
 using System.Threading;
@@ -11,9 +12,8 @@ namespace OpenVpn
 {
     class OpenVpnChild
     {
-        StreamWriter logFile;
+        string logFile;
         Process process;
-        ProcessStartInfo startInfo;
         System.Timers.Timer restartTimer;
         OpenVpnServiceConfiguration config;
         string configFile;
@@ -27,43 +27,14 @@ public OpenVpnChild(OpenVpnServiceConfiguration config, string configFile)
              * so make sure we are working on a copy */
             this.configFile = String.Copy(configFile);
             this.exitEvent = Path.GetFileName(configFile) + "_" + Process.GetCurrentProcess().Id.ToString();
-            var justFilename = System.IO.Path.GetFileName(configFile);
-            var logFilename = config.logDir + "\\" +
-                    justFilename.Substring(0, justFilename.Length - config.configExt.Length) + ".log";
+            var justFilename = Path.GetFileName(configFile);
+            logFile = Path.Combine(config.logDir, justFilename.Substring(0, justFilename.Length - config.configExt.Length) + ".log");
 
             // FIXME: if (!init_security_attributes_allow_all (&sa))
             //{
             //    MSG (M_SYSERR, "InitializeSecurityDescriptor start_" PACKAGE " failed");
             //    goto finish;
             //}
-
-            logFile = new StreamWriter(File.Open(logFilename,
-                config.logAppend ? FileMode.Append : FileMode.Create,
-                FileAccess.Write,
-                FileShare.Read), new UTF8Encoding(false));
-            logFile.AutoFlush = true;
-
-            /// SET UP PROCESS START INFO
-            string[] procArgs = {
-                "--config",
-                "\"" + configFile + "\"",
-                "--service ",
-                "\"" + exitEvent + "\"" + " 0"
-            };
-            this.startInfo = new System.Diagnostics.ProcessStartInfo()
-            {
-                RedirectStandardInput = true,
-                RedirectStandardOutput = true,
-                RedirectStandardError = true,
-                WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden,
-
-                FileName = config.exePath,
-                Arguments = String.Join(" ", procArgs),
-                WorkingDirectory = config.configDir,
-
-                UseShellExecute = false,
-                /* create_new_console is not exposed -- but we probably don't need it?*/
-            };
         }
 
         // set exit event so that openvpn will terminate
@@ -75,7 +46,7 @@ public void SignalProcess()
             }
             try
             {
-                if (!process.HasExited)
+                if (process != null && !process.HasExited)
                 {
 
                     try
@@ -117,7 +88,7 @@ public void StopProcess(int timeout)
             }
             try
             {
-                if (!process.WaitForExit(timeout))
+                if (process != null && !process.WaitForExit(timeout))
                 {
                     process.Exited -= Watchdog; // Don't restart the process after kill
                     process.Kill();
@@ -128,8 +99,8 @@ public void StopProcess(int timeout)
 
         public void Wait()
         {
-            process.WaitForExit();
-            logFile.Close();
+            if (process != null)
+                process.WaitForExit();
         }
 
         public void Restart()
@@ -139,7 +110,7 @@ public void Restart()
                 restartTimer.Stop();
             }
             /* try-catch... because there could be a concurrency issue (write-after-read) here? */
-            if (!process.HasExited)
+            if (process != null && !process.HasExited)
             {
                 process.Exited -= Watchdog;
                 process.Exited += FastRestart; // Restart the process after kill
@@ -158,12 +129,6 @@ public void Restart()
             }
         }
 
-        private void WriteToLog(object sendingProcess, DataReceivedEventArgs e)
-        {
-            if (e != null)
-                logFile.WriteLine(e.Data);
-        }
-
         /// Restart after 10 seconds
         /// For use with unexpected terminations
         private void Watchdog(object sender, EventArgs e)
@@ -193,21 +158,53 @@ private void FastRestart(object sender, EventArgs e)
             restartTimer.Start();
         }
 
+        private const string PipeName = @"openvpn\service";
+
         public void Start()
         {
-            process = new System.Diagnostics.Process();
+            using (var pipeClient = new NamedPipeClientStream(".", PipeName, PipeDirection.InOut, PipeOptions.Asynchronous))
+            {
+                config.LogMessage("Connecting to iservice pipe...");
+                pipeClient.Connect(5000);
 
-            process.StartInfo = startInfo;
-            process.EnableRaisingEvents = true;
+                using (var writer = new BinaryWriter(pipeClient, Encoding.Unicode))
+                using (var reader = new StreamReader(pipeClient, Encoding.Unicode))
+                {
+                    // send startup info
+                    var logOption = config.logAppend ? "--log-append " : "--log";
+                    var cmdLine = $"{logOption} \"{logFile}\" --config \"{configFile}\" --service \"{exitEvent}\" 0 --pull-filter ignore route-method";
 
-            process.OutputDataReceived += WriteToLog;
-            process.ErrorDataReceived += WriteToLog;
-            process.Exited += Watchdog;
+                    // config_dir + \0 + options + \0 + password + \0
+                    var startupInfo = $"{config.configDir}\0{cmdLine}\0\0";
 
-            process.Start();
-            process.BeginErrorReadLine();
-            process.BeginOutputReadLine();
-            process.PriorityClass = config.priorityClass;
+                    byte[] messageBytes = Encoding.Unicode.GetBytes(startupInfo);
+                    writer.Write(messageBytes);
+                    writer.Flush();
+
+                    config.LogMessage("Sent startupInfo to iservice");
+
+                    // read openvpn process pid from the pipe
+                    string[] lines = { reader.ReadLine(), reader.ReadLine() };
+
+                    config.LogMessage($"Read from iservice: {string.Join(" ", lines)}");
+                    var errorCode = Convert.ToInt32(lines[0], 16);
+
+                    if (errorCode == 0)
+                    {
+                        var pid = Convert.ToInt32(lines[1], 16);
+
+                        process = Process.GetProcessById(pid);
+                        process.PriorityClass = config.priorityClass;
+                        process.EnableRaisingEvents = true;
+                        process.Exited += Watchdog;
+
+                        config.LogMessage($"Add watchdog for openvpn process, pid {pid}");
+                    } else
+                    {
+                        config.LogMessage("Error getting openvpn process pid", EventLogEntryType.Error);
+                    }
+                }
+            }
         }
     }
 }