1 files changed, 86 insertions, 0 deletions
diff --git a/security/sandbox/linux/reporter/SandboxReporter.h b/security/sandbox/linux/reporter/SandboxReporter.h
new file mode 100644
index 0000000000..0969111c9c
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+++ b/security/sandbox/linux/reporter/SandboxReporter.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_SandboxReporter_h
+#define mozilla_SandboxReporter_h
+
+#include "SandboxReporterCommon.h"
+
+#include "base/platform_thread.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Types.h"
+#include "mozilla/UniquePtr.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+
+// This object collects the SandboxReport messages from all of the
+// child processes, submits them to Telemetry, and maintains a ring
+// buffer of the last kSandboxReporterBufferSize reports.
+class SandboxReporter final : public PlatformThread::Delegate {
+ public:
+  // For normal use, don't construct this directly; use the
+  // Singleton() method.
+  //
+  // For unit testing, use this constructor followed by the Init
+  // method; the object isn't usable unless Init returns true.
+  explicit SandboxReporter();
+  ~SandboxReporter();
+
+  // See above; this method is not thread-safe.
+  bool Init();
+
+  // Used in GeckoChildProcessHost to connect the child process's
+  // client to this report collector.
+  void GetClientFileDescriptorMapping(int* aSrcFd, int* aDstFd) const;
+
+  // A snapshot of the report ring buffer; element 0 of `mReports` is
+  // the `mOffset`th report to be received, and so on.
+  struct Snapshot {
+    // The buffer has to fit in memory, but the total number of
+    // reports received in the session can increase without bound and
+    // could potentially overflow a uint32_t, so this is 64-bit.
+    // (It's exposed to JS as a 53-bit int, effectively, but that
+    // should also be large enough.)
+    uint64_t mOffset;
+    nsTArray<SandboxReport> mReports;
+  };
+
+  // Read the ring buffer contents; this method is thread-safe.
+  Snapshot GetSnapshot();
+
+  // Gets or creates the singleton report collector.  Crashes if
+  // initialization fails (if a socketpair and/or thread can't be
+  // created, there was almost certainly about to be a crash anyway).
+  // Thread-safe as long as the pointer isn't used during/after XPCOM
+  // shutdown.
+  static SandboxReporter* Singleton();
+
+ private:
+  // These are constant over the life of the object:
+  int mClientFd;
+  int mServerFd;
+  PlatformThreadHandle mThread;
+
+  Mutex mMutex MOZ_UNANNOTATED;
+  // These are protected by mMutex:
+  UniquePtr<SandboxReport[]> mBuffer;
+  uint64_t mCount;
+
+  static StaticAutoPtr<SandboxReporter> sSingleton;
+
+  void ThreadMain(void) override;
+  void AddOne(const SandboxReport& aReport);
+};
+
+// This is a constant so the % operations can be optimized.  This is
+// exposed in the header so that unit tests can see it.
+static const size_t kSandboxReporterBufferSize = 32;
+
+}  // namespace mozilla
+
+#endif  // mozilla_SandboxReporter_h