| // Copyright 2021 The ChromiumOS Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef DLP_FANOTIFY_READER_THREAD_H_ |
| #define DLP_FANOTIFY_READER_THREAD_H_ |
| |
| #include <memory> |
| |
| #include "base/files/scoped_file.h" |
| #include "base/memory/scoped_refptr.h" |
| #include "base/task/sequenced_task_runner.h" |
| #include "base/threading/platform_thread.h" |
| #include <base/threading/watchdog.h> |
| #include "dlp/dlp_metrics.h" |
| |
| namespace dlp { |
| |
| // Reads events from fanotify file descriptor and post them to the delegate. |
| class FanotifyReaderThread : public base::PlatformThread::Delegate { |
| public: |
| // Watchdog waiting for timely (1sec) reply to fanotify file access. |
| // Crashes the daemon if it hangs. |
| class FanotifyReplyWatchdog : public base::Watchdog::Delegate { |
| public: |
| FanotifyReplyWatchdog(); |
| FanotifyReplyWatchdog(const FanotifyReplyWatchdog&) = delete; |
| FanotifyReplyWatchdog& operator=(const FanotifyReplyWatchdog&) = delete; |
| ~FanotifyReplyWatchdog() override; |
| |
| // Enables and disables the watchdog. |
| void Arm(); |
| void Disarm(); |
| |
| private: |
| // base::Watchdog::Delegate overrides: |
| void Alarm() override; |
| |
| base::Watchdog watchdog_; |
| }; |
| |
| class Delegate { |
| public: |
| // Request to process the file |inode| open request from process |pid|. |
| // |fd| is the file descriptor to the file. |
| virtual void OnFileOpenRequested( |
| ino_t inode, |
| int pid, |
| base::ScopedFD fd, |
| std::unique_ptr<FanotifyReplyWatchdog> watchdog) = 0; |
| |
| // Called when a file with |inode| was deleted. The file might already not |
| // exist on the filesystem. |
| virtual void OnFileDeleted(ino_t inode) = 0; |
| |
| // Called when an error occurres. |
| virtual void OnFanotifyError(FanotifyError error) = 0; |
| |
| protected: |
| virtual ~Delegate() = default; |
| }; |
| |
| FanotifyReaderThread( |
| scoped_refptr<base::SequencedTaskRunner> parent_task_runner, |
| Delegate* delegate); |
| ~FanotifyReaderThread() override; |
| |
| // Starts the thread to read events from |fanotify_fd|. |
| void StartThread(int fanotify_fd); |
| |
| private: |
| // base::PlatformThread::Delegate overrides: |
| void ThreadMain() override; |
| |
| void RunLoop(); |
| |
| void ForwardUMAErrorToParentThread(FanotifyError error); |
| |
| // Task runner from which this thread is started and where the delegate is |
| // running. |
| scoped_refptr<base::SequencedTaskRunner> parent_task_runner_; |
| Delegate* const delegate_; |
| int fanotify_fd_ = -1; |
| base::PlatformThreadHandle handle_; |
| }; |
| |
| } // namespace dlp |
| |
| #endif // DLP_FANOTIFY_READER_THREAD_H_ |