зеркало из https://github.com/mozilla/gecko-dev.git
67 строки
2.0 KiB
C++
67 строки
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_SandboxChroot_h
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#define mozilla_SandboxChroot_h
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#include <pthread.h>
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#include "mozilla/Attributes.h"
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// This class uses the chroot(2) system call and Linux namespaces to
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// revoke the process's access to the filesystem. It requires that
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// the process be able to create user namespaces; this is the
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// kHasUserNamespaces in common/SandboxInfo.h.
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//
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// Usage: call Prepare() from a thread with CAP_SYS_CHROOT in its
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// effective capability set, then later call Invoke() when ready to
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// drop filesystem access. Prepare() creates a thread to do the
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// chrooting, so the caller can (and should!) drop its own
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// capabilities afterwards. When Invoke() returns, the thread will
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// have exited.
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//
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// (Exception: on Android/B2G <= KitKat, because of how pthread_join
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// is implemented, the thread may still exist, but it will not have
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// capabilities. Accordingly, on such systems, be careful about
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// namespaces or other resources the thread might have inherited.)
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//
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// Prepare() can fail (return false); for example, if it doesn't have
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// CAP_SYS_CHROOT or if it can't create a directory to chroot into.
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//
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// The root directory will be empty and deleted, so the process will
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// not be able to create new entries in it regardless of permissions.
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namespace mozilla {
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class SandboxChroot final {
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public:
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SandboxChroot();
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~SandboxChroot();
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bool Prepare();
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void Invoke();
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private:
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enum Command {
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NO_THREAD,
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NO_COMMAND,
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DO_CHROOT,
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JUST_EXIT,
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};
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pthread_t mThread;
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pthread_mutex_t mMutex;
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pthread_cond_t mWakeup;
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Command mCommand;
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int mFd;
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void ThreadMain();
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static void* StaticThreadMain(void* aVoidPtr);
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bool SendCommand(Command aComm);
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};
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} // namespace mozilla
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#endif // mozilla_SandboxChroot_h
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