mandoline sandbox: prewarm libraries before we raise the sandbox.

mandoline/app/desktop/linux_sandbox.h

-// Copyright 2015 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 MANDOLINE_APP_DESKTOP_LINUX_SANDBOX_H_
-#define MANDOLINE_APP_DESKTOP_LINUX_SANDBOX_H_
-
-#include "base/files/scoped_file.h"
-#include "sandbox/linux/bpf_dsl/bpf_dsl.h"
-#include "sandbox/linux/bpf_dsl/policy.h"
-#include "sandbox/linux/syscall_broker/broker_process.h"
-
-namespace mandoline {
-
-// Encapsulates all tasks related to raising the sandbox for mandoline.
-class LinuxSandbox {
- public:
-  explicit LinuxSandbox(
-      const std::vector<sandbox::syscall_broker::BrokerFilePermission>&
-          permissions);
-  ~LinuxSandbox();
-
-  // Returns a vector of file permissions needed to load libraries.
-  static std::vector<sandbox::syscall_broker::BrokerFilePermission>
-  GetPermissions();
-
-  // Grabs a file descriptor to /proc.
-  void Warmup();
-
-  // Puts the user in a new PID namespace.
-  void EngageNamespaceSandbox();
-
-  // Starts a broker process and sets up seccomp-bpf to delegate decisions to
-  // it.
-  void EngageSeccompSandbox();
-
-  // Performs the dropping of access to the outside world (drops the reference
-  // to /proc acquired in Warmup().
-  void Seal();
-
- private:
-  bool warmed_up_;
-  base::ScopedFD proc_fd_;
-  scoped_ptr<sandbox::syscall_broker::BrokerProcess> broker_;
-  scoped_ptr<sandbox::bpf_dsl::Policy> policy_;
-
-  DISALLOW_COPY_AND_ASSIGN(LinuxSandbox);
-};
-
-}  // namespace mandoline
-
-#endif  // MANDOLINE_APP_DESKTOP_LINUX_SANDBOX_H_