New NaCl zygote implementation 2

content/common/zygote_fork_delegate_linux.h

+// Copyright (c) 2011 The Chromium 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 CONTENT_COMMON_ZYGOTE_FORK_DELEGATE_LINUX_H_
+#define CONTENT_COMMON_ZYGOTE_FORK_DELEGATE_LINUX_H_
+#pragma once
+
+#include <unistd.h>
+
+#include "base/basictypes.h"
+
+class ZygoteForkDelegate {
+ public:
+  // A ZygoteForkDelegate is created during Chrome linux zygote
+  // initialization, and provides "fork()" functionality with
+  // as an alternative to forking the zygote. A new delegate is
+  // passed in as an argument to ZygoteMain().
+  ZygoteForkDelegate() {}
+  virtual ~ZygoteForkDelegate() {}
+  // Initialization happens in the zygote after it has been
+  // started by ZygoteMain.
+  virtual void Init(const bool sandboxed,
+                    const int browserdesc,
+                    const int sandboxdesc) = 0;
+  // Returns 'true' if the delegate would like to handle a given
+  // fork request. Otherwise returns false.
+  virtual bool CanHelp(const std::string& process_type) = 0;
+  // Delegate forks, returning a -1 on failure. Outside the
+  // suid sandbox, Fork() returns the Linux process ID. Inside
+  // the sandbox, returns a positive integer, with PID discovery
+  // handled by the sandbox.
+  virtual pid_t Fork(const std::vector<int>& fds) = 0;
+  // After a successful for, signal the child to indicate that
+  // the child's PID has been received. Also communicate the
+  // channel switch as a part of acknowledgement message.
+  virtual bool AckChild(const int fd, const std::string& channel_switch) = 0;
+};
+
+class NullForkDelegate : public ZygoteForkDelegate {
+ public:
+  NullForkDelegate() {}
+  ~NullForkDelegate() {}
+  virtual void Init(const bool sandboxed,
+                    const int browserdesc,
+                    const int sandboxdesc) {}
+  virtual bool CanHelp(const std::string& process_type) { return false; }
+  virtual pid_t Fork(const std::vector<int>& fds) { return -1; }
+  virtual bool AckChild(const int fd, const std::string& channel_switch) {
+    return false;
+  }
+};
+
+#endif  // CONTENT_COMMON_ZYGOTE_FORK_DELEGATE_LINUX_H_