1 files changed, 175 insertions, 0 deletions
diff --git a/ipc/glue/NodeChannel.h b/ipc/glue/NodeChannel.h
new file mode 100644
index 0000000000..eae6cb655e
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+++ b/ipc/glue/NodeChannel.h
@@ -0,0 +1,175 @@
+/* -*- 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_ipc_NodeChannel_h
+#define mozilla_ipc_NodeChannel_h
+
+#include "mojo/core/ports/node.h"
+#include "mojo/core/ports/node_delegate.h"
+#include "base/process.h"
+#include "chrome/common/ipc_message.h"
+#include "chrome/common/ipc_channel.h"
+#include "mozilla/ipc/ProtocolUtils.h"
+#include "nsISupports.h"
+#include "nsTHashMap.h"
+#include "mozilla/Queue.h"
+#include "mozilla/DataMutex.h"
+#include "mozilla/UniquePtr.h"
+
+#ifdef FUZZING_SNAPSHOT
+#  include "mozilla/fuzzing/IPCFuzzController.h"
+#endif
+
+namespace mozilla::ipc {
+
+class NodeController;
+
+// Represents a live connection between our Node and a remote process. This
+// object acts as an IPC::Channel listener and performs basic processing on
+// messages as they're passed between processes.
+
+class NodeChannel final : public IPC::Channel::Listener {
+  using NodeName = mojo::core::ports::NodeName;
+  using PortName = mojo::core::ports::PortName;
+
+#ifdef FUZZING_SNAPSHOT
+  // Required because IPCFuzzController calls OnMessageReceived.
+  friend class mozilla::fuzzing::IPCFuzzController;
+#endif
+
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY(NodeChannel, Destroy())
+
+  struct Introduction {
+    NodeName mName;
+    IPC::Channel::ChannelHandle mHandle;
+    IPC::Channel::Mode mMode;
+    base::ProcessId mMyPid = base::kInvalidProcessId;
+    base::ProcessId mOtherPid = base::kInvalidProcessId;
+  };
+
+  class Listener {
+   public:
+    virtual ~Listener() = default;
+
+    NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
+
+    virtual void OnEventMessage(const NodeName& aFromNode,
+                                UniquePtr<IPC::Message> aMessage) = 0;
+    virtual void OnBroadcast(const NodeName& aFromNode,
+                             UniquePtr<IPC::Message> aMessage) = 0;
+    virtual void OnIntroduce(const NodeName& aFromNode,
+                             Introduction aIntroduction) = 0;
+    virtual void OnRequestIntroduction(const NodeName& aFromNode,
+                                       const NodeName& aName) = 0;
+    virtual void OnAcceptInvite(const NodeName& aFromNode,
+                                const NodeName& aRealName,
+                                const PortName& aInitialPort) = 0;
+    virtual void OnChannelError(const NodeName& aFromNode) = 0;
+  };
+
+  NodeChannel(const NodeName& aName, UniquePtr<IPC::Channel> aChannel,
+              Listener* aListener,
+              base::ProcessId aPid = base::kInvalidProcessId);
+
+  // Send the given message over this peer channel link. May be called from any
+  // thread.
+  void SendEventMessage(UniquePtr<IPC::Message> aMessage);
+
+  // Ask the broker process to broadcast this message to every node. May be
+  // called from any thread.
+  void Broadcast(UniquePtr<IPC::Message> aMessage);
+
+  // Ask the broker process to introduce this node to another node with the
+  // given name. May be called from any thread.
+  void RequestIntroduction(const NodeName& aPeerName);
+
+  // Send an introduction to the target node. May be called from any thread.
+  void Introduce(Introduction aIntroduction);
+
+  void AcceptInvite(const NodeName& aRealName, const PortName& aInitialPort);
+
+  // The PID of the remote process, once known. May be called from any thread.
+  base::ProcessId OtherPid() const { return mOtherPid; }
+
+  // Start communicating with the remote process using this NodeChannel. MUST BE
+  // CALLED FROM THE IO THREAD.
+  void Start(bool aCallConnect = true);
+
+  // Stop communicating with the remote process using this NodeChannel, MUST BE
+  // CALLED FROM THE IO THREAD.
+  void Close();
+
+  // Only ever called by NodeController to update the name after an invite has
+  // completed. MUST BE CALLED FROM THE IO THREAD.
+  void SetName(const NodeName& aNewName) { mName = aNewName; }
+
+#ifdef FUZZING_SNAPSHOT
+  // MUST BE CALLED FROM THE IO THREAD.
+  const NodeName& GetName() { return mName; }
+#endif
+
+#ifdef XP_MACOSX
+  // Called by the GeckoChildProcessHost to provide the task_t for the peer
+  // process. MUST BE CALLED FROM THE IO THREAD.
+  void SetMachTaskPort(task_t aTask);
+#endif
+
+ private:
+  ~NodeChannel();
+
+  void Destroy();
+  void FinalDestroy();
+
+  // Update the known PID for the remote process. IO THREAD ONLY
+  void SetOtherPid(base::ProcessId aNewPid);
+
+  void SendMessage(UniquePtr<IPC::Message> aMessage);
+
+  // IPC::Channel::Listener implementation
+  void OnMessageReceived(UniquePtr<IPC::Message> aMessage) override;
+  void OnChannelConnected(base::ProcessId aPeerPid) override;
+  void OnChannelError() override;
+
+  // NOTE: This strong reference will create a reference cycle between the
+  // listener and the NodeChannel while it is in use. The Listener must clear
+  // its reference to the NodeChannel to avoid leaks before shutdown.
+  const RefPtr<Listener> mListener;
+
+  // The apparent name of this Node. This may change during the invite process
+  // while waiting for the remote node name to be communicated to us.
+
+  // WARNING: This must only be accessed on the IO thread.
+  NodeName mName;
+
+  // NOTE: This won't change once the connection has been established, but may
+  // be `-1` until then. This will only be written to on the IO thread, but may
+  // be read from other threads.
+  std::atomic<base::ProcessId> mOtherPid;
+
+  // WARNING: Most methods on the IPC::Channel are only safe to call on the IO
+  // thread, however it is safe to call `Send()` and `IsClosed()` from other
+  // threads. See IPC::Channel's documentation for details.
+  const mozilla::UniquePtr<IPC::Channel> mChannel;
+
+  // The state will start out as `State::Active`, and will only transition to
+  // `State::Closed` on the IO thread. If a Send fails, the state will
+  // transition to `State::Closing`, and a runnable will be dispatched to the
+  // I/O thread to notify callbacks.
+  enum class State { Active, Closing, Closed };
+  std::atomic<State> mState = State::Active;
+
+#ifdef FUZZING_SNAPSHOT
+  std::atomic<bool> mBlockSendRecv = false;
+#endif
+
+  // WARNING: Must only be accessed on the IO thread.
+  WeakPtr<IPC::Channel::Listener> mExistingListener;
+};
+
+}  // namespace mozilla::ipc
+
+#endif