vpn-manager: Add l2tp/ipsec vpn manager

service_manager.h

Index: service_manager.h
diff --git a/service_manager.h b/service_manager.h
new file mode 100644
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+++ b/service_manager.h
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+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef _VPN_MANAGER_SERVICE_MANAGER_H_
+#define _VPN_MANAGER_SERVICE_MANAGER_H_
+
+#include <string>
+
+#include "base/file_path.h"
+#include "gtest/gtest_prod.h"  // for FRIEND_TEST
+
+class ScopedTempDir;
+
+// Generic code to manage setting up and stopping a set of layered
+// tunnel services.  This object contains the code to manage a single
+// layer.  Services are meant to be started from outermost to innermost.
+// Services are meant to be stopped from the innermost out.  To
+// stop the entire set of services, call Stop on the innermost.
+// Services go from not-yet-started to started to in_running to
+// was_stopped.
+class ServiceManager {
+ public:
+  ServiceManager(const std::string& service_name);
+  virtual ~ServiceManager();
+
+  // Initialize directories used by services.  |scoped_temp_dir| will
+  // be set to manage an appropriate temp directory.  This function
+  // uses a reference to |scoped_temp_dir| and so its lifetime must be
+  // equal to that of all objects derived from ServiceManager.
+  static void InitializeDirectories(ScopedTempDir* scoped_temp_path);
+
+  // Call to initiate this service.  If starting fails immediately this
+  // returns false.  If something fails after this returns, OnStopped
+  // will be called.  Code outside of the service manager stack
+  // must only call Start on the outermost function.
+  virtual bool Start() = 0;
+
+  // Callback when this service has successfully started.
+  virtual void OnStarted();
+
+  // Call to stop this service.  Must not be called on a separate
+  // thread from Start().  Code outside of the service manager stack
+  // must only call Stop on the innermost service.  It is ok to
+  // stop an already stopped service.
+  virtual void Stop() = 0;
+
+  // Returns the maximum amount of time to wait before this call should be
+  // called again in milliseconds.
+  virtual int Poll() = 0;
+
+  // Process output from child process.
+  virtual void ProcessOutput() = 0;
+
+  // Returns if |pid| is a child process of this service.
+  virtual bool IsChild(pid_t pid) = 0;
+
+  // Callback when this service has stopped after having started
+  // successfully.  |was_error| indicates if an error occurred.
+  virtual void OnStopped(bool was_error);
+
+  // Queries if this service is currently running.
+  bool is_running() {
+    return is_running_;
+  }
+
+  // Queries if this service was once running and is now stopped.
+  bool was_stopped() {
+    return was_stopped_;
+  }
+
+  // Set up layering between two service managers |outer| and |inner|.
+  // This function may be called multiple times to chain servics together,
+  // for instance:
+  //   ServiceManager::SetLayerOrder(&turkey, &duck);
+  //   ServiceManager::SetLayerOrder(&duck, &chicken);
+  static void SetLayerOrder(ServiceManager* outer,
+                            ServiceManager* inner) {
+    outer->inner_service_ = inner;
+    inner->outer_service_ = outer;
+  }
+
+  const std::string& service_name() {
+    return service_name_;
+  }
+
+  // Repeat data from the given |fd| which is assumed to be ready
+  // and send it out to syslog, placing |prefix| before each line
+  // of output.

[petkov, 2011/03/11 19:12:53]

The amount of data repeat per call is undefined? Document |partial_line|

[kmixter1, 2011/03/11 20:53:04]

Done.

+  static void WriteFdToSyslog(int fd, const std::string& prefix,
+                              std::string* partial_line);
+
+ protected:
+  friend class IpsecManagerTest;
+  friend class L2tpManagerTest;
+  friend class ServiceManagerTest;
+  FRIEND_TEST(L2tpManagerTest, PollNothingIfRunning);
+  FRIEND_TEST(IpsecManagerTest, PollNothingIfRunning);
+  FRIEND_TEST(ServiceManagerTest, InitializeDirectories);
+  FRIEND_TEST(ServiceManagerTest, OnStoppedFromFailure);
+  FRIEND_TEST(ServiceManagerTest, OnStoppedFromSuccess);
+
+  ServiceManager* inner_service() { return inner_service_; }
+
+  ServiceManager* outer_service() { return outer_service_; }
+
+  static const FilePath* temp_path() { return temp_path_; }
+
+ private:
+  // Indicates if this service is currently running.
+  bool is_running_;
+
+  // Indicates if this service was running and is now stopped.
+  bool was_stopped_;
+
+  // Pointer to the next layer or NULL if innermost.
+  ServiceManager* inner_service_;
+
+  // Pointer to the outer layer or NULL if outermost.
+  ServiceManager* outer_service_;
+
+  // Name of this service.
+  std::string service_name_;
+
+  // Path to temporary directory on cryptohome.
+  static const FilePath* temp_path_;
+
+  // Path to base directory of temporary directory on cryptohome.
+  static const char* temp_base_path_;
+};
+
+#endif  // _VPN_MANAGER_SERVICE_MANAGER_H_