Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

46 files changed, 6610 insertions, 0 deletions

diff --git a/dom/network/Connection.cpp b/dom/network/Connection.cpp
new file mode 100644
index 0000000000..217a937cf6
--- /dev/null
+++ b/dom/network/Connection.cpp
@@ -0,0 +1,88 @@
+/* -*- 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/. */
+
+#include "Connection.h"
+#include "ConnectionMainThread.h"
+#include "ConnectionWorker.h"
+#include "Constants.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/dom/WorkerPrivate.h"
+
+/**
+ * We have to use macros here because our leak analysis tool things we are
+ * leaking strings when we have |static const nsString|. Sad :(
+ */
+#define CHANGE_EVENT_NAME u"typechange"_ns
+
+namespace mozilla::dom::network {
+
+// Don't use |Connection| alone, since that confuses nsTraceRefcnt since
+// we're not the only class with that name.
+NS_IMPL_ISUPPORTS_INHERITED0(dom::network::Connection, DOMEventTargetHelper)
+
+Connection::Connection(nsPIDOMWindowInner* aWindow,
+                       bool aShouldResistFingerprinting)
+    : DOMEventTargetHelper(aWindow),
+      mShouldResistFingerprinting(aShouldResistFingerprinting),
+      mType(static_cast<ConnectionType>(kDefaultType)),
+      mIsWifi(kDefaultIsWifi),
+      mDHCPGateway(kDefaultDHCPGateway),
+      mBeenShutDown(false) {
+  Telemetry::Accumulate(Telemetry::NETWORK_CONNECTION_COUNT, 1);
+}
+
+Connection::~Connection() {
+  NS_ASSERT_OWNINGTHREAD(Connection);
+  MOZ_ASSERT(mBeenShutDown);
+}
+
+void Connection::Shutdown() {
+  NS_ASSERT_OWNINGTHREAD(Connection);
+
+  if (mBeenShutDown) {
+    return;
+  }
+
+  mBeenShutDown = true;
+  ShutdownInternal();
+}
+
+JSObject* Connection::WrapObject(JSContext* aCx,
+                                 JS::Handle<JSObject*> aGivenProto) {
+  return NetworkInformation_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void Connection::Update(ConnectionType aType, bool aIsWifi,
+                        uint32_t aDHCPGateway, bool aNotify) {
+  NS_ASSERT_OWNINGTHREAD(Connection);
+
+  ConnectionType previousType = mType;
+
+  mType = aType;
+  mIsWifi = aIsWifi;
+  mDHCPGateway = aDHCPGateway;
+
+  if (aNotify && previousType != aType && !mShouldResistFingerprinting) {
+    DispatchTrustedEvent(CHANGE_EVENT_NAME);
+  }
+}
+
+/* static */
+Connection* Connection::CreateForWindow(nsPIDOMWindowInner* aWindow,
+                                        bool aShouldResistFingerprinting) {
+  MOZ_ASSERT(aWindow);
+  return new ConnectionMainThread(aWindow, aShouldResistFingerprinting);
+}
+
+/* static */
+already_AddRefed<Connection> Connection::CreateForWorker(
+    WorkerPrivate* aWorkerPrivate, ErrorResult& aRv) {
+  MOZ_ASSERT(aWorkerPrivate);
+  aWorkerPrivate->AssertIsOnWorkerThread();
+  return ConnectionWorker::Create(aWorkerPrivate, aRv);
+}
+
+}  // namespace mozilla::dom::network
diff --git a/dom/network/Connection.h b/dom/network/Connection.h
new file mode 100644
index 0000000000..9d18ad089b
--- /dev/null
+++ b/dom/network/Connection.h
@@ -0,0 +1,99 @@
+/* -*- 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_dom_network_Connection_h
+#define mozilla_dom_network_Connection_h
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/NetworkInformationBinding.h"
+#include "nsCycleCollectionParticipant.h"
+
+namespace mozilla {
+
+namespace hal {
+class NetworkInformation;
+}  // namespace hal
+
+namespace dom {
+
+class WorkerPrivate;
+
+namespace network {
+
+class Connection : public DOMEventTargetHelper {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+
+  static Connection* CreateForWindow(nsPIDOMWindowInner* aWindow,
+                                     bool aShouldResistFingerprinting);
+
+  static already_AddRefed<Connection> CreateForWorker(
+      WorkerPrivate* aWorkerPrivate, ErrorResult& aRv);
+
+  void Shutdown();
+
+  // WebIDL
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  ConnectionType Type() const {
+    return mShouldResistFingerprinting
+               ? static_cast<ConnectionType>(ConnectionType::Unknown)
+               : mType;
+  }
+
+  bool GetIsWifi() const {
+    NS_ASSERT_OWNINGTHREAD(Connection);
+
+    return mIsWifi;
+  }
+  uint32_t GetDhcpGateway() const {
+    NS_ASSERT_OWNINGTHREAD(Connection);
+
+    return mDHCPGateway;
+  }
+
+  IMPL_EVENT_HANDLER(typechange)
+
+ protected:
+  Connection(nsPIDOMWindowInner* aWindow, bool aShouldResistFingerprinting);
+  virtual ~Connection();
+
+  void Update(ConnectionType aType, bool aIsWifi, uint32_t aDHCPGateway,
+              bool aNotify);
+
+  virtual void ShutdownInternal() = 0;
+
+ private:
+  /**
+   * If ResistFingerprinting is enabled or disabled.
+   */
+  bool mShouldResistFingerprinting;
+
+  /**
+   * The type of current connection.
+   */
+  ConnectionType mType;
+
+  /**
+   * If the connection is WIFI
+   */
+  bool mIsWifi;
+
+  /**
+   * DHCP Gateway information for IPV4, in network byte order. 0 if unassigned.
+   */
+  uint32_t mDHCPGateway;
+
+  bool mBeenShutDown;
+};
+
+}  // namespace network
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_network_Connection_h
diff --git a/dom/network/ConnectionMainThread.cpp b/dom/network/ConnectionMainThread.cpp
new file mode 100644
index 0000000000..210cbaf015
--- /dev/null
+++ b/dom/network/ConnectionMainThread.cpp
@@ -0,0 +1,40 @@
+/* -*- 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/. */
+
+#include <limits>
+#include "mozilla/Hal.h"
+#include "ConnectionMainThread.h"
+
+namespace mozilla::dom::network {
+
+ConnectionMainThread::ConnectionMainThread(nsPIDOMWindowInner* aWindow,
+                                           bool aShouldResistFingerprinting)
+    : Connection(aWindow, aShouldResistFingerprinting) {
+  hal::RegisterNetworkObserver(this);
+
+  hal::NetworkInformation networkInfo;
+  hal::GetCurrentNetworkInformation(&networkInfo);
+
+  UpdateFromNetworkInfo(networkInfo, false);
+}
+
+ConnectionMainThread::~ConnectionMainThread() { Shutdown(); }
+
+void ConnectionMainThread::ShutdownInternal() {
+  hal::UnregisterNetworkObserver(this);
+}
+
+void ConnectionMainThread::UpdateFromNetworkInfo(
+    const hal::NetworkInformation& aNetworkInfo, bool aNotify) {
+  Update(static_cast<ConnectionType>(aNetworkInfo.type()),
+         aNetworkInfo.isWifi(), aNetworkInfo.dhcpGateway(), aNotify);
+}
+
+void ConnectionMainThread::Notify(const hal::NetworkInformation& aNetworkInfo) {
+  UpdateFromNetworkInfo(aNetworkInfo, true);
+}
+
+}  // namespace mozilla::dom::network
diff --git a/dom/network/ConnectionMainThread.h b/dom/network/ConnectionMainThread.h
new file mode 100644
index 0000000000..1e6a12f9b1
--- /dev/null
+++ b/dom/network/ConnectionMainThread.h
@@ -0,0 +1,40 @@
+/* -*- 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_dom_network_ConnectionMainThread_h
+#define mozilla_dom_network_ConnectionMainThread_h
+
+#include "Connection.h"
+#include "mozilla/Hal.h"
+#include "mozilla/Observer.h"
+
+namespace mozilla::dom::network {
+
+class ConnectionMainThread final : public Connection,
+                                   public hal::NetworkObserver {
+ public:
+  explicit ConnectionMainThread(nsPIDOMWindowInner* aWindow,
+                                bool aShouldResistFingerprinting);
+
+  // For IObserver
+  void Notify(const hal::NetworkInformation& aNetworkInfo) override;
+
+ private:
+  ~ConnectionMainThread();
+
+  virtual void ShutdownInternal() override;
+
+  /**
+   * Update the connection information stored in the object using a
+   * NetworkInformation object.
+   */
+  void UpdateFromNetworkInfo(const hal::NetworkInformation& aNetworkInfo,
+                             bool aNotify);
+};
+
+}  // namespace mozilla::dom::network
+
+#endif  // mozilla_dom_network_ConnectionMainThread_h
diff --git a/dom/network/ConnectionWorker.cpp b/dom/network/ConnectionWorker.cpp
new file mode 100644
index 0000000000..a72d771de0
--- /dev/null
+++ b/dom/network/ConnectionWorker.cpp
@@ -0,0 +1,213 @@
+/* -*- 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/. */
+
+#include <limits>
+#include "mozilla/Hal.h"
+#include "ConnectionWorker.h"
+#include "mozilla/dom/WorkerPrivate.h"
+#include "mozilla/dom/WorkerRef.h"
+#include "mozilla/dom/WorkerRunnable.h"
+#include "mozilla/dom/WorkerScope.h"
+
+namespace mozilla::dom::network {
+
+class ConnectionProxy final : public hal::NetworkObserver {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ConnectionProxy)
+
+  static already_AddRefed<ConnectionProxy> Create(
+      WorkerPrivate* aWorkerPrivate, ConnectionWorker* aConnection) {
+    RefPtr<ConnectionProxy> proxy = new ConnectionProxy(aConnection);
+
+    RefPtr<StrongWorkerRef> workerRef = StrongWorkerRef::Create(
+        aWorkerPrivate, "ConnectionProxy", [proxy]() { proxy->Shutdown(); });
+    if (NS_WARN_IF(!workerRef)) {
+      return nullptr;
+    }
+
+    proxy->mWorkerRef = new ThreadSafeWorkerRef(workerRef);
+    return proxy.forget();
+  }
+
+  ThreadSafeWorkerRef* WorkerRef() const { return mWorkerRef; }
+
+  // For IObserver - main-thread only.
+  void Notify(const hal::NetworkInformation& aNetworkInfo) override;
+
+  void Shutdown();
+
+  void Update(ConnectionType aType, bool aIsWifi, uint32_t aDHCPGateway) {
+    MOZ_ASSERT(mConnection);
+    MOZ_ASSERT(IsCurrentThreadRunningWorker());
+    mConnection->Update(aType, aIsWifi, aDHCPGateway, true);
+  }
+
+ private:
+  explicit ConnectionProxy(ConnectionWorker* aConnection)
+      : mConnection(aConnection) {}
+
+  ~ConnectionProxy() = default;
+
+  // Raw pointer because the ConnectionWorker keeps alive the proxy.
+  // This is touched only on the worker-thread and it's nullified when the
+  // shutdown procedure starts.
+  ConnectionWorker* mConnection;
+
+  RefPtr<ThreadSafeWorkerRef> mWorkerRef;
+};
+
+namespace {
+
+// This class initializes the hal observer on the main-thread.
+class InitializeRunnable : public WorkerMainThreadRunnable {
+ private:
+  // raw pointer because this is a sync runnable.
+  ConnectionProxy* mProxy;
+  hal::NetworkInformation& mNetworkInfo;
+
+ public:
+  InitializeRunnable(WorkerPrivate* aWorkerPrivate, ConnectionProxy* aProxy,
+                     hal::NetworkInformation& aNetworkInfo)
+      : WorkerMainThreadRunnable(aWorkerPrivate,
+                                 "ConnectionWorker :: Initialize"_ns),
+        mProxy(aProxy),
+        mNetworkInfo(aNetworkInfo) {
+    MOZ_ASSERT(aProxy);
+    aWorkerPrivate->AssertIsOnWorkerThread();
+  }
+
+  bool MainThreadRun() override {
+    MOZ_ASSERT(NS_IsMainThread());
+    hal::RegisterNetworkObserver(mProxy);
+    hal::GetCurrentNetworkInformation(&mNetworkInfo);
+    return true;
+  }
+};
+
+// This class turns down the hal observer on the main-thread.
+class ShutdownRunnable : public WorkerMainThreadRunnable {
+ private:
+  // raw pointer because this is a sync runnable.
+  ConnectionProxy* mProxy;
+
+ public:
+  ShutdownRunnable(WorkerPrivate* aWorkerPrivate, ConnectionProxy* aProxy)
+      : WorkerMainThreadRunnable(aWorkerPrivate,
+                                 "ConnectionWorker :: Shutdown"_ns),
+        mProxy(aProxy) {
+    MOZ_ASSERT(aProxy);
+    aWorkerPrivate->AssertIsOnWorkerThread();
+  }
+
+  bool MainThreadRun() override {
+    MOZ_ASSERT(NS_IsMainThread());
+    hal::UnregisterNetworkObserver(mProxy);
+    return true;
+  }
+};
+
+class NotifyRunnable : public WorkerRunnable {
+ private:
+  RefPtr<ConnectionProxy> mProxy;
+
+  const ConnectionType mConnectionType;
+  const bool mIsWifi;
+  const uint32_t mDHCPGateway;
+
+ public:
+  NotifyRunnable(WorkerPrivate* aWorkerPrivate, ConnectionProxy* aProxy,
+                 ConnectionType aType, bool aIsWifi, uint32_t aDHCPGateway)
+      : WorkerRunnable(aWorkerPrivate),
+        mProxy(aProxy),
+        mConnectionType(aType),
+        mIsWifi(aIsWifi),
+        mDHCPGateway(aDHCPGateway) {
+    MOZ_ASSERT(aProxy);
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  bool WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate) override {
+    aWorkerPrivate->AssertIsOnWorkerThread();
+    mProxy->Update(mConnectionType, mIsWifi, mDHCPGateway);
+    return true;
+  }
+};
+
+}  // anonymous namespace
+
+/* static */
+already_AddRefed<ConnectionWorker> ConnectionWorker::Create(
+    WorkerPrivate* aWorkerPrivate, ErrorResult& aRv) {
+  bool shouldResistFingerprinting =
+      aWorkerPrivate->GlobalScope()->ShouldResistFingerprinting(
+          RFPTarget::Unknown);
+  RefPtr<ConnectionWorker> c = new ConnectionWorker(shouldResistFingerprinting);
+  c->mProxy = ConnectionProxy::Create(aWorkerPrivate, c);
+  if (!c->mProxy) {
+    aRv.ThrowTypeError("The Worker thread is shutting down.");
+    return nullptr;
+  }
+
+  hal::NetworkInformation networkInfo;
+  RefPtr<InitializeRunnable> runnable =
+      new InitializeRunnable(aWorkerPrivate, c->mProxy, networkInfo);
+
+  runnable->Dispatch(Canceling, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  c->Update(static_cast<ConnectionType>(networkInfo.type()),
+            networkInfo.isWifi(), networkInfo.dhcpGateway(), false);
+  return c.forget();
+}
+
+ConnectionWorker::ConnectionWorker(bool aShouldResistFingerprinting)
+    : Connection(nullptr, aShouldResistFingerprinting) {
+  MOZ_ASSERT(IsCurrentThreadRunningWorker());
+}
+
+ConnectionWorker::~ConnectionWorker() { Shutdown(); }
+
+void ConnectionWorker::ShutdownInternal() {
+  MOZ_ASSERT(IsCurrentThreadRunningWorker());
+  mProxy->Shutdown();
+}
+
+void ConnectionProxy::Notify(const hal::NetworkInformation& aNetworkInfo) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  RefPtr<NotifyRunnable> runnable =
+      new NotifyRunnable(mWorkerRef->Private(), this,
+                         static_cast<ConnectionType>(aNetworkInfo.type()),
+                         aNetworkInfo.isWifi(), aNetworkInfo.dhcpGateway());
+  runnable->Dispatch();
+}
+
+void ConnectionProxy::Shutdown() {
+  MOZ_ASSERT(IsCurrentThreadRunningWorker());
+
+  // Already shut down.
+  if (!mConnection) {
+    return;
+  }
+
+  mConnection = nullptr;
+
+  RefPtr<ShutdownRunnable> runnable =
+      new ShutdownRunnable(mWorkerRef->Private(), this);
+
+  ErrorResult rv;
+  // This runnable _must_ be executed.
+  runnable->Dispatch(Killing, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+  }
+
+  mWorkerRef = nullptr;
+}
+
+}  // namespace mozilla::dom::network
diff --git a/dom/network/ConnectionWorker.h b/dom/network/ConnectionWorker.h
new file mode 100644
index 0000000000..7a705e2f08
--- /dev/null
+++ b/dom/network/ConnectionWorker.h
@@ -0,0 +1,34 @@
+/* -*- 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_dom_network_ConnectionWorker_h
+#define mozilla_dom_network_ConnectionWorker_h
+
+#include "Connection.h"
+
+namespace mozilla::dom::network {
+
+class ConnectionProxy;
+
+class ConnectionWorker final : public Connection {
+  friend class ConnectionProxy;
+
+ public:
+  static already_AddRefed<ConnectionWorker> Create(
+      WorkerPrivate* aWorkerPrivate, ErrorResult& aRv);
+
+ private:
+  explicit ConnectionWorker(bool aShouldResistFingerprinting);
+  ~ConnectionWorker();
+
+  virtual void ShutdownInternal() override;
+
+  RefPtr<ConnectionProxy> mProxy;
+};
+
+}  // namespace mozilla::dom::network
+
+#endif  // mozilla_dom_network_ConnectionWorker_h
diff --git a/dom/network/Constants.h b/dom/network/Constants.h
new file mode 100644
index 0000000000..53817bd6b7
--- /dev/null
+++ b/dom/network/Constants.h
@@ -0,0 +1,21 @@
+/* -*- 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_dom_network_Constants_h__
+#define mozilla_dom_network_Constants_h__
+
+/**
+ * A set of constants to be used by network backends.
+ */
+namespace mozilla::dom::network {
+
+static const uint32_t kDefaultType = 5;  // ConnectionType::None
+static const bool kDefaultIsWifi = false;
+static const uint32_t kDefaultDHCPGateway = 0;
+
+}  // namespace mozilla::dom::network
+
+#endif  // mozilla_dom_network_Constants_h__
diff --git a/dom/network/PTCPServerSocket.ipdl b/dom/network/PTCPServerSocket.ipdl
new file mode 100644
index 0000000000..8370cf945c
--- /dev/null
+++ b/dom/network/PTCPServerSocket.ipdl
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+
+/* 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/. */
+
+include protocol PNecko;
+include protocol PTCPSocket;
+
+include "mozilla/net/NeckoMessageUtils.h";
+include "mozilla/dom/network/TCPServerSocketParent.h";
+include "mozilla/dom/network/TCPServerSocketChild.h";
+
+namespace mozilla {
+namespace net {
+
+//-------------------------------------------------------------------
+[ManualDealloc, ChildImpl="mozilla::dom::TCPServerSocketChild", ParentImpl="mozilla::dom::TCPServerSocketParent"]
+protocol PTCPServerSocket
+{
+  manager PNecko;
+
+parent:
+  async Close();
+  async RequestDelete();
+
+child:
+  async CallbackAccept(PTCPSocket socket);
+  async __delete__();
+};
+
+} // namespace net
+} // namespace mozilla
+
diff --git a/dom/network/PTCPSocket.ipdl b/dom/network/PTCPSocket.ipdl
new file mode 100644
index 0000000000..c255408dd7
--- /dev/null
+++ b/dom/network/PTCPSocket.ipdl
@@ -0,0 +1,79 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+
+/* 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/. */
+
+include protocol PNecko;
+
+include "mozilla/net/NeckoMessageUtils.h";
+include "mozilla/dom/network/TCPSocketParent.h";
+include "mozilla/dom/network/TCPSocketChild.h";
+
+using struct mozilla::void_t from "mozilla/ipc/IPCCore.h";
+
+struct TCPError {
+  nsString name;
+  nsString message;
+  nsresult errorCode;
+};
+
+union SendableData {
+  uint8_t[];
+  nsCString;
+};
+
+union CallbackData {
+  void_t;
+  SendableData;
+  TCPError;
+};
+
+namespace mozilla {
+namespace net {
+
+//-------------------------------------------------------------------
+[ManualDealloc, ChildImpl="mozilla::dom::TCPSocketChild", ParentImpl="mozilla::dom::TCPSocketParent"]
+protocol PTCPSocket
+{
+  manager PNecko;
+
+parent:
+  // Forward calling to child's open() method to parent, expect TCPOptions
+  // is expanded to |useSSL| (from TCPOptions.useSecureTransport) and
+  // |binaryType| (from TCPOption.binaryType).
+  async Open(nsString host, uint16_t port, bool useSSL, bool useArrayBuffers);
+
+  async Data(SendableData data);
+
+  // Forward calling to child's upgradeToSecure() method to parent.
+  async StartTLS();
+
+  // Forward calling to child's send() method to parent.
+  async Suspend();
+
+  // Forward calling to child's resume() method to parent.
+  async Resume();
+
+  // Forward calling to child's close() method to parent.
+  async Close();
+
+child:
+  // Forward events that are dispatched by parent.
+  async Callback(nsString type, CallbackData data, uint32_t readyState);
+
+  // Update child's bufferedAmount when parent's bufferedAmount is updated.
+  // trackingNumber is also passed back to child to ensure the bufferedAmount
+  // is corresponding the last call to send().
+  async UpdateBufferedAmount(uint32_t bufferedAmount, uint32_t trackingNumber);
+
+both:
+  async RequestDelete();
+  async __delete__();
+};
+
+
+} // namespace net
+} // namespace mozilla
+
diff --git a/dom/network/PUDPSocket.ipdl b/dom/network/PUDPSocket.ipdl
new file mode 100644
index 0000000000..cc5a1729f3
--- /dev/null
+++ b/dom/network/PUDPSocket.ipdl
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et tw=80 ft=cpp : */
+
+/* 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/. */
+
+include protocol PNecko;
+include protocol PBackground;
+
+include IPCStream;
+
+include "mozilla/net/NeckoMessageUtils.h";
+include "mozilla/net/DNS.h";
+include "prio.h";
+include "mozilla/dom/network/UDPSocketParent.h";
+include "mozilla/dom/network/UDPSocketChild.h";
+
+using mozilla::net::NetAddr from "mozilla/net/DNS.h";
+using struct mozilla::void_t from "mozilla/ipc/IPCCore.h";
+
+struct UDPAddressInfo {
+  nsCString addr;
+  uint16_t port;
+};
+
+union UDPSocketAddr {
+  UDPAddressInfo;
+  NetAddr;
+};
+
+union UDPData {
+  uint8_t[];
+  IPCStream;
+};
+
+namespace mozilla {
+namespace net {
+
+//-------------------------------------------------------------------
+[ManualDealloc, ChildImpl="mozilla::dom::UDPSocketChild", ParentImpl="mozilla::dom::UDPSocketParent"]
+protocol PUDPSocket
+{
+  manager PNecko or PBackground;
+
+parent:
+  async Bind(UDPAddressInfo addressInfo, bool addressReuse, bool loopback,
+             uint32_t recvBufferSize, uint32_t sendBufferSize);
+  async Connect(UDPAddressInfo addressInfo);
+
+  async OutgoingData(UDPData data, UDPSocketAddr addr);
+
+  async JoinMulticast(nsCString multicastAddress, nsCString iface);
+  async LeaveMulticast(nsCString multicastAddress, nsCString iface);
+
+  async Close();
+
+  async RequestDelete();
+
+child:
+  async CallbackOpened(UDPAddressInfo addressInfo);
+  async CallbackConnected(UDPAddressInfo addressInfo);
+  async CallbackClosed();
+  async CallbackReceivedData(UDPAddressInfo addressInfo, uint8_t[] data);
+  async CallbackError(nsCString message, nsCString filename, uint32_t lineNumber);
+  async __delete__();
+};
+
+
+} // namespace net
+} // namespace mozilla
+
diff --git a/dom/network/TCPServerSocket.cpp b/dom/network/TCPServerSocket.cpp
new file mode 100644
index 0000000000..b39cad0e14
--- /dev/null
+++ b/dom/network/TCPServerSocket.cpp
@@ -0,0 +1,172 @@
+/* -*- 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/. */
+
+#include "mozilla/dom/TCPServerSocketBinding.h"
+#include "mozilla/dom/TCPServerSocketEvent.h"
+#include "mozilla/dom/TCPSocketBinding.h"
+#include "TCPServerSocketParent.h"
+#include "TCPServerSocketChild.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/ErrorResult.h"
+#include "TCPServerSocket.h"
+#include "TCPSocket.h"
+#include "nsComponentManagerUtils.h"
+
+using namespace mozilla::dom;
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(TCPServerSocket)
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(TCPServerSocket,
+                                               DOMEventTargetHelper)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(TCPServerSocket,
+                                                  DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mServerSocket)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mServerBridgeChild)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mServerBridgeParent)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(TCPServerSocket,
+                                                DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mServerSocket)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mServerBridgeChild)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mServerBridgeParent)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_ADDREF_INHERITED(TCPServerSocket, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(TCPServerSocket, DOMEventTargetHelper)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPServerSocket)
+  NS_INTERFACE_MAP_ENTRY(nsIServerSocketListener)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+TCPServerSocket::TCPServerSocket(nsIGlobalObject* aGlobal, uint16_t aPort,
+                                 bool aUseArrayBuffers, uint16_t aBacklog)
+    : DOMEventTargetHelper(aGlobal),
+      mPort(aPort),
+      mBacklog(aBacklog),
+      mUseArrayBuffers(aUseArrayBuffers) {}
+
+TCPServerSocket::~TCPServerSocket() = default;
+
+nsresult TCPServerSocket::Init() {
+  if (mServerSocket || mServerBridgeChild) {
+    NS_WARNING("Child TCPServerSocket is already listening.");
+    return NS_ERROR_FAILURE;
+  }
+
+  if (XRE_GetProcessType() == GeckoProcessType_Content) {
+    mServerBridgeChild =
+        new TCPServerSocketChild(this, mPort, mBacklog, mUseArrayBuffers);
+    return NS_OK;
+  }
+
+  nsresult rv;
+  mServerSocket =
+      do_CreateInstance("@mozilla.org/network/server-socket;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mServerSocket->Init(mPort, false, mBacklog);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mServerSocket->GetPort(&mPort);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mServerSocket->AsyncListen(this);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+already_AddRefed<TCPServerSocket> TCPServerSocket::Constructor(
+    const GlobalObject& aGlobal, uint16_t aPort,
+    const ServerSocketOptions& aOptions, uint16_t aBacklog,
+    mozilla::ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
+  if (!global) {
+    aRv = NS_ERROR_FAILURE;
+    return nullptr;
+  }
+  bool useArrayBuffers =
+      aOptions.mBinaryType == TCPSocketBinaryType::Arraybuffer;
+  RefPtr<TCPServerSocket> socket =
+      new TCPServerSocket(global, aPort, useArrayBuffers, aBacklog);
+  nsresult rv = socket->Init();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    aRv = NS_ERROR_FAILURE;
+    return nullptr;
+  }
+  return socket.forget();
+}
+
+uint16_t TCPServerSocket::LocalPort() const { return mPort; }
+
+void TCPServerSocket::Close() {
+  if (mServerBridgeChild) {
+    mServerBridgeChild->Close();
+  }
+  if (mServerSocket) {
+    mServerSocket->Close();
+  }
+}
+
+void TCPServerSocket::FireEvent(const nsAString& aType, TCPSocket* aSocket) {
+  TCPServerSocketEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mSocket = aSocket;
+
+  RefPtr<TCPServerSocketEvent> event =
+      TCPServerSocketEvent::Constructor(this, aType, init);
+  event->SetTrusted(true);
+  DispatchEvent(*event);
+
+  if (mServerBridgeParent) {
+    mServerBridgeParent->OnConnect(event);
+  }
+}
+
+NS_IMETHODIMP
+TCPServerSocket::OnSocketAccepted(nsIServerSocket* aServer,
+                                  nsISocketTransport* aTransport) {
+  nsCOMPtr<nsIGlobalObject> global = GetOwnerGlobal();
+  RefPtr<TCPSocket> socket =
+      TCPSocket::CreateAcceptedSocket(global, aTransport, mUseArrayBuffers);
+  FireEvent(u"connect"_ns, socket);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPServerSocket::OnStopListening(nsIServerSocket* aServer, nsresult aStatus) {
+  if (aStatus != NS_BINDING_ABORTED) {
+    RefPtr<Event> event = new Event(GetOwner());
+    event->InitEvent(u"error"_ns, false, false);
+    event->SetTrusted(true);
+    DispatchEvent(*event);
+
+    NS_WARNING("Server socket was closed by unexpected reason.");
+    return NS_ERROR_FAILURE;
+  }
+  mServerSocket = nullptr;
+  return NS_OK;
+}
+
+nsresult TCPServerSocket::AcceptChildSocket(TCPSocketChild* aSocketChild) {
+  nsCOMPtr<nsIGlobalObject> global = GetOwnerGlobal();
+  NS_ENSURE_TRUE(global, NS_ERROR_FAILURE);
+  RefPtr<TCPSocket> socket =
+      TCPSocket::CreateAcceptedSocket(global, aSocketChild, mUseArrayBuffers);
+  NS_ENSURE_TRUE(socket, NS_ERROR_FAILURE);
+  FireEvent(u"connect"_ns, socket);
+  return NS_OK;
+}
+
+void TCPServerSocket::SetServerBridgeParent(
+    TCPServerSocketParent* aBridgeParent) {
+  mServerBridgeParent = aBridgeParent;
+}
+
+JSObject* TCPServerSocket::WrapObject(JSContext* aCx,
+                                      JS::Handle<JSObject*> aGivenProto) {
+  return TCPServerSocket_Binding::Wrap(aCx, this, aGivenProto);
+}
diff --git a/dom/network/TCPServerSocket.h b/dom/network/TCPServerSocket.h
new file mode 100644
index 0000000000..550cba683e
--- /dev/null
+++ b/dom/network/TCPServerSocket.h
@@ -0,0 +1,81 @@
+/* -*- 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_dom_TCPServerSocket_h
+#define mozilla_dom_TCPServerSocket_h
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "nsIServerSocket.h"
+
+namespace mozilla {
+class ErrorResult;
+namespace dom {
+
+struct ServerSocketOptions;
+class GlobalObject;
+class TCPSocket;
+class TCPSocketChild;
+class TCPServerSocketChild;
+class TCPServerSocketParent;
+
+class TCPServerSocket final : public DOMEventTargetHelper,
+                              public nsIServerSocketListener {
+ public:
+  TCPServerSocket(nsIGlobalObject* aGlobal, uint16_t aPort,
+                  bool aUseArrayBuffers, uint16_t aBacklog);
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(TCPServerSocket,
+                                                         DOMEventTargetHelper)
+  NS_DECL_NSISERVERSOCKETLISTENER
+
+  nsPIDOMWindowInner* GetParentObject() const { return GetOwner(); }
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  nsresult Init();
+
+  uint16_t LocalPort() const;
+  void Close();
+
+  static already_AddRefed<TCPServerSocket> Constructor(
+      const GlobalObject& aGlobal, uint16_t aPort,
+      const ServerSocketOptions& aOptions, uint16_t aBacklog,
+      mozilla::ErrorResult& aRv);
+
+  IMPL_EVENT_HANDLER(connect);
+  IMPL_EVENT_HANDLER(error);
+
+  // Relay an accepted socket notification from the parent process and
+  // initialize this object with an existing child actor for the new socket.
+  nsresult AcceptChildSocket(TCPSocketChild* aSocketChild);
+  // Associate this object with an IPC actor in the parent process to relay
+  // notifications to content processes.
+  void SetServerBridgeParent(TCPServerSocketParent* aBridgeParent);
+
+ private:
+  ~TCPServerSocket();
+  // Dispatch a TCPServerSocketEvent event of a given type at this object.
+  void FireEvent(const nsAString& aType, TCPSocket* aSocket);
+
+  // The server socket associated with this object.
+  nsCOMPtr<nsIServerSocket> mServerSocket;
+  // The IPC actor in the content process.
+  RefPtr<TCPServerSocketChild> mServerBridgeChild;
+  // The IPC actor in the parent process.
+  RefPtr<TCPServerSocketParent> mServerBridgeParent;
+  int32_t mPort;
+  uint16_t mBacklog;
+  // True if any accepted sockets should use array buffers for received
+  // messages.
+  bool mUseArrayBuffers;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_TCPServerSocket_h
diff --git a/dom/network/TCPServerSocketChild.cpp b/dom/network/TCPServerSocketChild.cpp
new file mode 100644
index 0000000000..544c5391ee
--- /dev/null
+++ b/dom/network/TCPServerSocketChild.cpp
@@ -0,0 +1,75 @@
+/* -*- 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/. */
+
+#include "TCPServerSocketChild.h"
+#include "TCPSocketChild.h"
+#include "TCPServerSocket.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/dom/PBrowserChild.h"
+#include "mozilla/dom/BrowserChild.h"
+#include "nsJSUtils.h"
+#include "jsfriendapi.h"
+
+using mozilla::net::gNeckoChild;
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION(TCPServerSocketChildBase, mServerSocket)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TCPServerSocketChildBase)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TCPServerSocketChildBase)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPServerSocketChildBase)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+TCPServerSocketChildBase::TCPServerSocketChildBase() : mIPCOpen(false) {}
+
+TCPServerSocketChildBase::~TCPServerSocketChildBase() = default;
+
+NS_IMETHODIMP_(MozExternalRefCountType) TCPServerSocketChild::Release(void) {
+  nsrefcnt refcnt = TCPServerSocketChildBase::Release();
+  if (refcnt == 1 && mIPCOpen) {
+    PTCPServerSocketChild::SendRequestDelete();
+    return 1;
+  }
+  return refcnt;
+}
+
+TCPServerSocketChild::TCPServerSocketChild(TCPServerSocket* aServerSocket,
+                                           uint16_t aLocalPort,
+                                           uint16_t aBacklog,
+                                           bool aUseArrayBuffers) {
+  mServerSocket = aServerSocket;
+  AddIPDLReference();
+  gNeckoChild->SendPTCPServerSocketConstructor(this, aLocalPort, aBacklog,
+                                               aUseArrayBuffers);
+}
+
+void TCPServerSocketChildBase::ReleaseIPDLReference() {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  this->Release();
+}
+
+void TCPServerSocketChildBase::AddIPDLReference() {
+  MOZ_ASSERT(!mIPCOpen);
+  mIPCOpen = true;
+  this->AddRef();
+}
+
+TCPServerSocketChild::~TCPServerSocketChild() = default;
+
+mozilla::ipc::IPCResult TCPServerSocketChild::RecvCallbackAccept(
+    PTCPSocketChild* psocket) {
+  RefPtr<TCPSocketChild> socket = static_cast<TCPSocketChild*>(psocket);
+  nsresult rv = mServerSocket->AcceptChildSocket(socket);
+  NS_ENSURE_SUCCESS(rv, IPC_OK());
+  return IPC_OK();
+}
+
+void TCPServerSocketChild::Close() { SendClose(); }
+
+}  // namespace mozilla::dom
diff --git a/dom/network/TCPServerSocketChild.h b/dom/network/TCPServerSocketChild.h
new file mode 100644
index 0000000000..b6773cb61b
--- /dev/null
+++ b/dom/network/TCPServerSocketChild.h
@@ -0,0 +1,59 @@
+/* -*- 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_dom_TCPServerSocketChild_h
+#define mozilla_dom_TCPServerSocketChild_h
+
+#include "mozilla/net/PTCPServerSocketChild.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+
+#define TCPSERVERSOCKETCHILD_CID                     \
+  {                                                  \
+    0x41a77ec8, 0xfd86, 0x409e, {                    \
+      0xae, 0xa9, 0xaf, 0x2c, 0xa4, 0x07, 0xef, 0x8e \
+    }                                                \
+  }
+
+class nsITCPServerSocketInternal;
+
+namespace mozilla::dom {
+
+class TCPServerSocket;
+
+class TCPServerSocketChildBase : public nsISupports {
+ public:
+  NS_DECL_CYCLE_COLLECTION_CLASS(TCPServerSocketChildBase)
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  void AddIPDLReference();
+  void ReleaseIPDLReference();
+
+ protected:
+  TCPServerSocketChildBase();
+  virtual ~TCPServerSocketChildBase();
+
+  RefPtr<TCPServerSocket> mServerSocket;
+  bool mIPCOpen;
+};
+
+class TCPServerSocketChild : public mozilla::net::PTCPServerSocketChild,
+                             public TCPServerSocketChildBase {
+ public:
+  NS_IMETHOD_(MozExternalRefCountType) Release() override;
+
+  TCPServerSocketChild(TCPServerSocket* aServerSocket, uint16_t aLocalPort,
+                       uint16_t aBacklog, bool aUseArrayBuffers);
+  ~TCPServerSocketChild();
+
+  void Close();
+
+  mozilla::ipc::IPCResult RecvCallbackAccept(PTCPSocketChild* socket);
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_TCPServerSocketChild_h
diff --git a/dom/network/TCPServerSocketParent.cpp b/dom/network/TCPServerSocketParent.cpp
new file mode 100644
index 0000000000..c73ee7e0ff
--- /dev/null
+++ b/dom/network/TCPServerSocketParent.cpp
@@ -0,0 +1,118 @@
+/* -*- 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/. */
+
+#include "TCPServerSocket.h"
+#include "TCPServerSocketParent.h"
+#include "nsJSUtils.h"
+#include "TCPSocket.h"
+#include "TCPSocketParent.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/BrowserParent.h"
+#include "mozilla/dom/TCPServerSocketEvent.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION(TCPServerSocketParent, mServerSocket)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TCPServerSocketParent)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TCPServerSocketParent)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPServerSocketParent)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+void TCPServerSocketParent::ReleaseIPDLReference() {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  this->Release();
+}
+
+void TCPServerSocketParent::AddIPDLReference() {
+  MOZ_ASSERT(!mIPCOpen);
+  mIPCOpen = true;
+  this->AddRef();
+}
+
+TCPServerSocketParent::TCPServerSocketParent(PNeckoParent* neckoParent,
+                                             uint16_t aLocalPort,
+                                             uint16_t aBacklog,
+                                             bool aUseArrayBuffers)
+    : mNeckoParent(neckoParent), mIPCOpen(false) {
+  mServerSocket =
+      new TCPServerSocket(nullptr, aLocalPort, aUseArrayBuffers, aBacklog);
+  mServerSocket->SetServerBridgeParent(this);
+}
+
+TCPServerSocketParent::~TCPServerSocketParent() = default;
+
+void TCPServerSocketParent::Init() {
+  NS_ENSURE_SUCCESS_VOID(mServerSocket->Init());
+}
+
+nsresult TCPServerSocketParent::SendCallbackAccept(TCPSocketParent* socket) {
+  nsresult rv;
+
+  nsString host;
+  rv = socket->GetHost(host);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Failed to get host from nsITCPSocketParent");
+    return NS_ERROR_FAILURE;
+  }
+
+  uint16_t port;
+  rv = socket->GetPort(&port);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Failed to get port from nsITCPSocketParent");
+    return NS_ERROR_FAILURE;
+  }
+
+  if (mNeckoParent) {
+    if (mNeckoParent->SendPTCPSocketConstructor(socket, host, port)) {
+      // Call |AddIPDLReference| after the consructor message is sent
+      // successfully, otherwise |socket| could be leaked.
+      socket->AddIPDLReference();
+
+      mozilla::Unused << PTCPServerSocketParent::SendCallbackAccept(
+          WrapNotNull(socket));
+    } else {
+      NS_ERROR("Sending data from PTCPSocketParent was failed.");
+    }
+  } else {
+    NS_ERROR("The member value for NeckoParent is wrong.");
+  }
+  return NS_OK;
+}
+
+mozilla::ipc::IPCResult TCPServerSocketParent::RecvClose() {
+  NS_ENSURE_TRUE(mServerSocket, IPC_OK());
+  mServerSocket->Close();
+  return IPC_OK();
+}
+
+void TCPServerSocketParent::ActorDestroy(ActorDestroyReason why) {
+  if (mServerSocket) {
+    mServerSocket->Close();
+    mServerSocket = nullptr;
+  }
+  mNeckoParent = nullptr;
+}
+
+mozilla::ipc::IPCResult TCPServerSocketParent::RecvRequestDelete() {
+  mozilla::Unused << Send__delete__(this);
+  return IPC_OK();
+}
+
+void TCPServerSocketParent::OnConnect(TCPServerSocketEvent* event) {
+  RefPtr<TCPSocket> socket = event->Socket();
+
+  RefPtr<TCPSocketParent> socketParent = new TCPSocketParent();
+  socketParent->SetSocket(socket);
+
+  socket->SetSocketBridgeParent(socketParent);
+
+  SendCallbackAccept(socketParent);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/network/TCPServerSocketParent.h b/dom/network/TCPServerSocketParent.h
new file mode 100644
index 0000000000..bbebaa1860
--- /dev/null
+++ b/dom/network/TCPServerSocketParent.h
@@ -0,0 +1,54 @@
+/* -*- 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_dom_TCPServerSocketParent_h
+#define mozilla_dom_TCPServerSocketParent_h
+
+#include "mozilla/net/PNeckoParent.h"
+#include "mozilla/net/PTCPServerSocketParent.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla::dom {
+
+class TCPServerSocket;
+class TCPServerSocketEvent;
+class TCPSocketParent;
+
+class TCPServerSocketParent : public mozilla::net::PTCPServerSocketParent,
+                              public nsISupports {
+ public:
+  NS_DECL_CYCLE_COLLECTION_CLASS(TCPServerSocketParent)
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  TCPServerSocketParent(PNeckoParent* neckoParent, uint16_t aLocalPort,
+                        uint16_t aBacklog, bool aUseArrayBuffers);
+
+  void Init();
+
+  mozilla::ipc::IPCResult RecvClose();
+  mozilla::ipc::IPCResult RecvRequestDelete();
+
+  void AddIPDLReference();
+  void ReleaseIPDLReference();
+
+  void OnConnect(TCPServerSocketEvent* event);
+
+ private:
+  ~TCPServerSocketParent();
+
+  nsresult SendCallbackAccept(TCPSocketParent* socket);
+
+  virtual void ActorDestroy(ActorDestroyReason why) override;
+
+  PNeckoParent* mNeckoParent;
+  RefPtr<TCPServerSocket> mServerSocket;
+  bool mIPCOpen;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_TCPServerSocketParent_h
diff --git a/dom/network/TCPSocket.cpp b/dom/network/TCPSocket.cpp
new file mode 100644
index 0000000000..6dabd1a630
--- /dev/null
+++ b/dom/network/TCPSocket.cpp
@@ -0,0 +1,1157 @@
+/* -*- 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/. */
+
+#include "TCPServerSocket.h"
+#include "TCPSocket.h"
+#include "TCPSocketChild.h"
+#include "TCPSocketParent.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/SyncRunnable.h"
+#include "mozilla/dom/RootedDictionary.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/TCPSocketBinding.h"
+#include "mozilla/dom/TCPSocketErrorEvent.h"
+#include "mozilla/dom/TCPSocketErrorEventBinding.h"
+#include "mozilla/dom/TCPSocketEvent.h"
+#include "mozilla/dom/TCPSocketEventBinding.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsIArrayBufferInputStream.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncStreamCopier.h"
+#include "nsIBinaryInputStream.h"
+#include "nsICancelable.h"
+#include "nsIChannel.h"
+#include "nsIInputStream.h"
+#include "nsIInputStreamPump.h"
+#include "nsIMultiplexInputStream.h"
+#include "nsINSSErrorsService.h"
+#include "nsIObserverService.h"
+#include "nsIOutputStream.h"
+#include "nsIProtocolProxyService.h"
+#include "nsIScriptableInputStream.h"
+#include "nsISocketTransport.h"
+#include "nsISocketTransportService.h"
+#include "nsISupportsPrimitives.h"
+#include "nsITLSSocketControl.h"
+#include "nsITransport.h"
+#include "nsIURIMutator.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsServiceManagerUtils.h"
+#include "nsString.h"
+#include "nsStringStream.h"
+#include "secerr.h"
+#include "sslerr.h"
+
+#define BUFFER_SIZE 65536
+#define NETWORK_STATS_THRESHOLD 65536
+
+using namespace mozilla::dom;
+
+NS_IMPL_CYCLE_COLLECTION(LegacyMozTCPSocket, mGlobal)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(LegacyMozTCPSocket)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(LegacyMozTCPSocket)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(LegacyMozTCPSocket)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+LegacyMozTCPSocket::LegacyMozTCPSocket(nsPIDOMWindowInner* aWindow)
+    : mGlobal(do_QueryInterface(aWindow)) {}
+
+LegacyMozTCPSocket::~LegacyMozTCPSocket() = default;
+
+already_AddRefed<TCPSocket> LegacyMozTCPSocket::Open(
+    const nsAString& aHost, uint16_t aPort, const SocketOptions& aOptions,
+    mozilla::ErrorResult& aRv) {
+  AutoJSAPI api;
+  if (NS_WARN_IF(!api.Init(mGlobal))) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+  GlobalObject globalObj(api.cx(), mGlobal->GetGlobalJSObject());
+  return TCPSocket::Constructor(globalObj, aHost, aPort, aOptions, aRv);
+}
+
+already_AddRefed<TCPServerSocket> LegacyMozTCPSocket::Listen(
+    uint16_t aPort, const ServerSocketOptions& aOptions, uint16_t aBacklog,
+    mozilla::ErrorResult& aRv) {
+  AutoJSAPI api;
+  if (NS_WARN_IF(!api.Init(mGlobal))) {
+    return nullptr;
+  }
+  GlobalObject globalObj(api.cx(), mGlobal->GetGlobalJSObject());
+  return TCPServerSocket::Constructor(globalObj, aPort, aOptions, aBacklog,
+                                      aRv);
+}
+
+bool LegacyMozTCPSocket::WrapObject(JSContext* aCx,
+                                    JS::Handle<JSObject*> aGivenProto,
+                                    JS::MutableHandle<JSObject*> aReflector) {
+  return LegacyMozTCPSocket_Binding::Wrap(aCx, this, aGivenProto, aReflector);
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(TCPSocket)
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(TCPSocket, DOMEventTargetHelper)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(TCPSocket,
+                                                  DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTransport)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSocketInputStream)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSocketOutputStream)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInputStreamPump)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInputStreamScriptable)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInputStreamBinary)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPendingDataAfterStartTLS)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSocketBridgeChild)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSocketBridgeParent)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(TCPSocket, DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mTransport)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSocketInputStream)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSocketOutputStream)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mInputStreamPump)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mInputStreamScriptable)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mInputStreamBinary)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPendingDataAfterStartTLS)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSocketBridgeChild)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSocketBridgeParent)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_ADDREF_INHERITED(TCPSocket, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(TCPSocket, DOMEventTargetHelper)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPSocket)
+  NS_INTERFACE_MAP_ENTRY(nsITransportEventSink)
+  NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+  NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+  NS_INTERFACE_MAP_ENTRY(nsIInputStreamCallback)
+  NS_INTERFACE_MAP_ENTRY(nsIObserver)
+  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+  NS_INTERFACE_MAP_ENTRY(nsITCPSocketCallback)
+  NS_INTERFACE_MAP_ENTRY(nsIProtocolProxyCallback)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+TCPSocket::TCPSocket(nsIGlobalObject* aGlobal, const nsAString& aHost,
+                     uint16_t aPort, bool aSsl, bool aUseArrayBuffers)
+    : DOMEventTargetHelper(aGlobal),
+      mReadyState(TCPReadyState::Closed),
+      mUseArrayBuffers(aUseArrayBuffers),
+      mHost(aHost),
+      mPort(aPort),
+      mSsl(aSsl),
+      mAsyncCopierActive(false),
+      mWaitingForDrain(false),
+      mInnerWindowID(0),
+      mBufferedAmount(0),
+      mSuspendCount(0),
+      mTrackingNumber(0),
+      mWaitingForStartTLS(false),
+      mObserversActive(false) {
+  if (aGlobal) {
+    nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(aGlobal);
+    if (window) {
+      mInnerWindowID = window->WindowID();
+    }
+  }
+}
+
+TCPSocket::~TCPSocket() {
+  if (mObserversActive) {
+    nsCOMPtr<nsIObserverService> obs =
+        do_GetService("@mozilla.org/observer-service;1");
+    if (obs) {
+      obs->RemoveObserver(this, "inner-window-destroyed");
+      obs->RemoveObserver(this, "profile-change-net-teardown");
+    }
+  }
+}
+
+nsresult TCPSocket::CreateStream() {
+  nsresult rv =
+      mTransport->OpenInputStream(0, 0, 0, getter_AddRefs(mSocketInputStream));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mTransport->OpenOutputStream(nsITransport::OPEN_UNBUFFERED, 0, 0,
+                                    getter_AddRefs(mSocketOutputStream));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // If the other side is not listening, we will
+  // get an onInputStreamReady callback where available
+  // raises to indicate the connection was refused.
+  nsCOMPtr<nsIAsyncInputStream> asyncStream =
+      do_QueryInterface(mSocketInputStream);
+  NS_ENSURE_TRUE(asyncStream, NS_ERROR_NOT_AVAILABLE);
+
+  nsCOMPtr<nsISerialEventTarget> mainTarget = GetMainThreadSerialEventTarget();
+  rv = asyncStream->AsyncWait(this, nsIAsyncInputStream::WAIT_CLOSURE_ONLY, 0,
+                              mainTarget);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mUseArrayBuffers) {
+    mInputStreamBinary =
+        do_CreateInstance("@mozilla.org/binaryinputstream;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = mInputStreamBinary->SetInputStream(mSocketInputStream);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    mInputStreamScriptable =
+        do_CreateInstance("@mozilla.org/scriptableinputstream;1", &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = mInputStreamScriptable->Init(mSocketInputStream);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+nsresult TCPSocket::InitWithUnconnectedTransport(
+    nsISocketTransport* aTransport) {
+  mReadyState = TCPReadyState::Connecting;
+  mTransport = aTransport;
+
+  MOZ_ASSERT(XRE_GetProcessType() != GeckoProcessType_Content);
+
+  nsCOMPtr<nsISerialEventTarget> mainTarget = GetMainThreadSerialEventTarget();
+  mTransport->SetEventSink(this, mainTarget);
+
+  nsresult rv = CreateStream();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult TCPSocket::Init(nsIProxyInfo* aProxyInfo) {
+  nsCOMPtr<nsIObserverService> obs =
+      do_GetService("@mozilla.org/observer-service;1");
+  if (obs) {
+    mObserversActive = true;
+    obs->AddObserver(this, "inner-window-destroyed", true);  // weak reference
+    obs->AddObserver(this, "profile-change-net-teardown", true);  // weak ref
+  }
+
+  if (XRE_GetProcessType() == GeckoProcessType_Content) {
+    mReadyState = TCPReadyState::Connecting;
+
+    nsCOMPtr<nsISerialEventTarget> target;
+    if (nsCOMPtr<nsIGlobalObject> global = GetOwnerGlobal()) {
+      target = global->EventTargetFor(TaskCategory::Other);
+    }
+    mSocketBridgeChild = new TCPSocketChild(mHost, mPort, target);
+    mSocketBridgeChild->SendOpen(this, mSsl, mUseArrayBuffers);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsISocketTransportService> sts =
+      do_GetService("@mozilla.org/network/socket-transport-service;1");
+
+  AutoTArray<nsCString, 1> socketTypes;
+  if (mSsl) {
+    socketTypes.AppendElement("ssl"_ns);
+  } else {
+    socketTypes.AppendElement("starttls"_ns);
+  }
+  nsCOMPtr<nsISocketTransport> transport;
+  nsresult rv =
+      sts->CreateTransport(socketTypes, NS_ConvertUTF16toUTF8(mHost), mPort,
+                           aProxyInfo, nullptr, getter_AddRefs(transport));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return InitWithUnconnectedTransport(transport);
+}
+
+void TCPSocket::InitWithSocketChild(TCPSocketChild* aSocketBridge) {
+  mSocketBridgeChild = aSocketBridge;
+  mReadyState = TCPReadyState::Open;
+  mSocketBridgeChild->SetSocket(this);
+  mSocketBridgeChild->GetHost(mHost);
+  mSocketBridgeChild->GetPort(&mPort);
+}
+
+nsresult TCPSocket::InitWithTransport(nsISocketTransport* aTransport) {
+  mTransport = aTransport;
+  nsresult rv = CreateStream();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mReadyState = TCPReadyState::Open;
+  rv = CreateInputStreamPump();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString host;
+  mTransport->GetHost(host);
+  CopyUTF8toUTF16(host, mHost);
+  int32_t port;
+  mTransport->GetPort(&port);
+  mPort = port;
+
+  return NS_OK;
+}
+
+void TCPSocket::UpgradeToSecure(mozilla::ErrorResult& aRv) {
+  if (mReadyState != TCPReadyState::Open) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  if (mSsl) {
+    return;
+  }
+
+  mSsl = true;
+
+  if (mSocketBridgeChild) {
+    mSocketBridgeChild->SendStartTLS();
+    return;
+  }
+
+  if (!mAsyncCopierActive) {
+    ActivateTLS();
+  } else {
+    mWaitingForStartTLS = true;
+  }
+}
+
+namespace {
+class CopierCallbacks final : public nsIRequestObserver {
+  RefPtr<TCPSocket> mOwner;
+
+ public:
+  explicit CopierCallbacks(TCPSocket* aSocket) : mOwner(aSocket) {}
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIREQUESTOBSERVER
+ private:
+  ~CopierCallbacks() = default;
+};
+
+NS_IMPL_ISUPPORTS(CopierCallbacks, nsIRequestObserver)
+
+NS_IMETHODIMP
+CopierCallbacks::OnStartRequest(nsIRequest* aRequest) { return NS_OK; }
+
+NS_IMETHODIMP
+CopierCallbacks::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  mOwner->NotifyCopyComplete(aStatus);
+  mOwner = nullptr;
+  return NS_OK;
+}
+}  // unnamed namespace
+
+void TCPSocket::CalculateBufferedAmount() {
+  // Let's update the buffered amount of data.
+  uint64_t bufferedAmount = 0;
+  for (uint32_t i = 0, len = mPendingData.Length(); i < len; ++i) {
+    nsCOMPtr<nsIInputStream> stream = mPendingData[i];
+    uint64_t available = 0;
+    if (NS_SUCCEEDED(stream->Available(&available))) {
+      bufferedAmount += available;
+    }
+  }
+  mBufferedAmount = bufferedAmount;
+}
+
+nsresult TCPSocket::EnsureCopying() {
+  if (mAsyncCopierActive) {
+    return NS_OK;
+  }
+
+  mAsyncCopierActive = true;
+
+  nsresult rv;
+
+  nsCOMPtr<nsIMultiplexInputStream> multiplexStream =
+      do_CreateInstance("@mozilla.org/io/multiplex-input-stream;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIInputStream> stream = do_QueryInterface(multiplexStream);
+
+  while (!mPendingData.IsEmpty()) {
+    nsCOMPtr<nsIInputStream> stream = mPendingData[0];
+    multiplexStream->AppendStream(stream);
+    mPendingData.RemoveElementAt(0);
+  }
+
+  nsCOMPtr<nsIAsyncStreamCopier> copier =
+      do_CreateInstance("@mozilla.org/network/async-stream-copier;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsISocketTransportService> sts =
+      do_GetService("@mozilla.org/network/socket-transport-service;1");
+
+  nsCOMPtr<nsISerialEventTarget> target = do_QueryInterface(sts);
+  rv = copier->Init(stream, mSocketOutputStream, target,
+                    true,               /* source buffered */
+                    false,              /* sink buffered */
+                    BUFFER_SIZE, false, /* close source */
+                    false);             /* close sink */
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<CopierCallbacks> callbacks = new CopierCallbacks(this);
+  rv = copier->AsyncCopy(callbacks, nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+void TCPSocket::NotifyCopyComplete(nsresult aStatus) {
+  mAsyncCopierActive = false;
+  CalculateBufferedAmount();
+
+  if (mSocketBridgeParent && mSocketBridgeParent->IPCOpen()) {
+    mozilla::Unused << mSocketBridgeParent->SendUpdateBufferedAmount(
+        BufferedAmount(), mTrackingNumber);
+  }
+
+  if (NS_FAILED(aStatus)) {
+    MaybeReportErrorAndCloseIfOpen(aStatus);
+    return;
+  }
+
+  if (BufferedAmount() != 0) {
+    EnsureCopying();
+    return;
+  }
+
+  // Maybe we have some empty stream. We want to have an empty queue now.
+  mPendingData.Clear();
+
+  // If we are waiting for initiating starttls, we can begin to
+  // activate tls now.
+  if (mWaitingForStartTLS && mReadyState == TCPReadyState::Open) {
+    ActivateTLS();
+    mWaitingForStartTLS = false;
+    // If we have pending data, we should send them, or fire
+    // a drain event if we are waiting for it.
+    if (!mPendingDataAfterStartTLS.IsEmpty()) {
+      mPendingData = std::move(mPendingDataAfterStartTLS);
+      EnsureCopying();
+      return;
+    }
+  }
+
+  // If we have a connected child, we let the child decide whether
+  // ondrain should be dispatched.
+  if (mWaitingForDrain && !mSocketBridgeParent) {
+    mWaitingForDrain = false;
+    FireEvent(u"drain"_ns);
+  }
+
+  if (mReadyState == TCPReadyState::Closing) {
+    if (mSocketOutputStream) {
+      mSocketOutputStream->Close();
+      mSocketOutputStream = nullptr;
+    }
+    mReadyState = TCPReadyState::Closed;
+    FireEvent(u"close"_ns);
+  }
+}
+
+void TCPSocket::ActivateTLS() {
+  nsresult rv;
+  nsCOMPtr<nsIEventTarget> socketThread =
+      do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  bool alreadyOnSTST = false;
+  if (NS_FAILED(socketThread->IsOnCurrentThread(&alreadyOnSTST))) {
+    return;
+  }
+
+  if (alreadyOnSTST) {
+    ActivateTLSHelper();
+    return;
+  }
+
+  auto CallActivateTLS = [sock = RefPtr{this}]() mutable {
+    sock->ActivateTLSHelper();
+  };
+  mozilla::SyncRunnable::DispatchToThread(
+      socketThread,
+      NS_NewRunnableFunction("TCPSocket::UpgradeToSecure->ActivateTLSHelper",
+                             CallActivateTLS));
+}
+
+void TCPSocket::ActivateTLSHelper() {
+  nsCOMPtr<nsITLSSocketControl> tlsSocketControl;
+  mTransport->GetTlsSocketControl(getter_AddRefs(tlsSocketControl));
+  if (tlsSocketControl) {
+    tlsSocketControl->StartTLS();
+  }
+}
+
+NS_IMETHODIMP
+TCPSocket::FireErrorEvent(const nsAString& aName, const nsAString& aType,
+                          nsresult aErrorCode) {
+  if (mSocketBridgeParent) {
+    mSocketBridgeParent->FireErrorEvent(aName, aType, aErrorCode, mReadyState);
+    return NS_OK;
+  }
+
+  TCPSocketErrorEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mName = aName;
+  init.mMessage = aType;
+  static_assert(std::is_same_v<std::underlying_type_t<nsresult>, uint32_t>);
+  init.mErrorCode = uint32_t(aErrorCode);
+
+  RefPtr<TCPSocketErrorEvent> event =
+      TCPSocketErrorEvent::Constructor(this, u"error"_ns, init);
+  MOZ_ASSERT(event);
+  event->SetTrusted(true);
+  DispatchEvent(*event);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::FireEvent(const nsAString& aType) {
+  if (mSocketBridgeParent) {
+    mSocketBridgeParent->FireEvent(aType, mReadyState);
+    return NS_OK;
+  }
+
+  AutoJSAPI api;
+  if (NS_WARN_IF(!api.Init(GetOwnerGlobal()))) {
+    return NS_ERROR_FAILURE;
+  }
+  JS::Rooted<JS::Value> val(api.cx());
+  return FireDataEvent(api.cx(), aType, val);
+}
+
+NS_IMETHODIMP
+TCPSocket::FireDataArrayEvent(const nsAString& aType,
+                              const nsTArray<uint8_t>& buffer) {
+  AutoJSAPI api;
+  if (NS_WARN_IF(!api.Init(GetOwnerGlobal()))) {
+    return NS_ERROR_FAILURE;
+  }
+  JSContext* cx = api.cx();
+  JS::Rooted<JS::Value> val(cx);
+
+  bool ok = IPC::DeserializeArrayBuffer(cx, buffer, &val);
+  if (ok) {
+    return FireDataEvent(cx, aType, val);
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+TCPSocket::FireDataStringEvent(const nsAString& aType,
+                               const nsACString& aString) {
+  AutoJSAPI api;
+  if (NS_WARN_IF(!api.Init(GetOwnerGlobal()))) {
+    return NS_ERROR_FAILURE;
+  }
+  JSContext* cx = api.cx();
+  JS::Rooted<JS::Value> val(cx);
+
+  bool ok = ToJSValue(cx, NS_ConvertASCIItoUTF16(aString), &val);
+  if (ok) {
+    return FireDataEvent(cx, aType, val);
+  }
+  return NS_ERROR_FAILURE;
+}
+
+nsresult TCPSocket::FireDataEvent(JSContext* aCx, const nsAString& aType,
+                                  JS::Handle<JS::Value> aData) {
+  MOZ_ASSERT(!mSocketBridgeParent);
+
+  RootedDictionary<TCPSocketEventInit> init(aCx);
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mData = aData;
+
+  RefPtr<TCPSocketEvent> event = TCPSocketEvent::Constructor(this, aType, init);
+  event->SetTrusted(true);
+  DispatchEvent(*event);
+  return NS_OK;
+}
+
+JSObject* TCPSocket::WrapObject(JSContext* aCx,
+                                JS::Handle<JSObject*> aGivenProto) {
+  return TCPSocket_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void TCPSocket::GetHost(nsAString& aHost) { aHost.Assign(mHost); }
+
+uint32_t TCPSocket::Port() const { return mPort; }
+
+bool TCPSocket::Ssl() const { return mSsl; }
+
+void TCPSocket::Suspend() {
+  if (mSocketBridgeChild) {
+    mSocketBridgeChild->SendSuspend();
+    return;
+  }
+  if (mInputStreamPump) {
+    mInputStreamPump->Suspend();
+  }
+  mSuspendCount++;
+}
+
+void TCPSocket::Resume(mozilla::ErrorResult& aRv) {
+  if (mSocketBridgeChild) {
+    mSocketBridgeChild->SendResume();
+    return;
+  }
+  if (!mSuspendCount) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  if (mInputStreamPump) {
+    mInputStreamPump->Resume();
+  }
+  mSuspendCount--;
+}
+
+nsresult TCPSocket::MaybeReportErrorAndCloseIfOpen(nsresult status) {
+  // If we're closed, we've already reported the error or just don't need to
+  // report the error.
+  if (mReadyState == TCPReadyState::Closed) {
+    return NS_OK;
+  }
+
+  // go through ::Closing state and then mark ::Closed
+  Close();
+  mReadyState = TCPReadyState::Closed;
+
+  if (NS_FAILED(status)) {
+    // Convert the status code to an appropriate error message.
+
+    nsString errorType, errName;
+
+    // security module? (and this is an error)
+    if ((static_cast<uint32_t>(status) & 0xFF0000) == 0x5a0000) {
+      nsCOMPtr<nsINSSErrorsService> errSvc =
+          do_GetService("@mozilla.org/nss_errors_service;1");
+      // getErrorClass will throw a generic NS_ERROR_FAILURE if the error code
+      // is somehow not in the set of covered errors.
+      uint32_t errorClass;
+      nsresult rv = errSvc->GetErrorClass(status, &errorClass);
+      if (NS_FAILED(rv)) {
+        errorType.AssignLiteral("SecurityProtocol");
+      } else {
+        switch (errorClass) {
+          case nsINSSErrorsService::ERROR_CLASS_BAD_CERT:
+            errorType.AssignLiteral("SecurityCertificate");
+            break;
+          default:
+            errorType.AssignLiteral("SecurityProtocol");
+            break;
+        }
+      }
+
+      // NSS_SEC errors (happen below the base value because of negative vals)
+      if ((static_cast<int32_t>(status) & 0xFFFF) <
+          abs(nsINSSErrorsService::NSS_SEC_ERROR_BASE)) {
+        switch (static_cast<SECErrorCodes>(status)) {
+          case SEC_ERROR_EXPIRED_CERTIFICATE:
+            errName.AssignLiteral("SecurityExpiredCertificateError");
+            break;
+          case SEC_ERROR_REVOKED_CERTIFICATE:
+            errName.AssignLiteral("SecurityRevokedCertificateError");
+            break;
+            // per bsmith, we will be unable to tell these errors apart very
+            // soon, so it makes sense to just folder them all together already.
+          case SEC_ERROR_UNKNOWN_ISSUER:
+          case SEC_ERROR_UNTRUSTED_ISSUER:
+          case SEC_ERROR_UNTRUSTED_CERT:
+          case SEC_ERROR_CA_CERT_INVALID:
+            errName.AssignLiteral("SecurityUntrustedCertificateIssuerError");
+            break;
+          case SEC_ERROR_INADEQUATE_KEY_USAGE:
+            errName.AssignLiteral("SecurityInadequateKeyUsageError");
+            break;
+          case SEC_ERROR_CERT_SIGNATURE_ALGORITHM_DISABLED:
+            errName.AssignLiteral(
+                "SecurityCertificateSignatureAlgorithmDisabledError");
+            break;
+          default:
+            errName.AssignLiteral("SecurityError");
+            break;
+        }
+      } else {
+        // NSS_SSL errors
+        switch (static_cast<SSLErrorCodes>(status)) {
+          case SSL_ERROR_NO_CERTIFICATE:
+            errName.AssignLiteral("SecurityNoCertificateError");
+            break;
+          case SSL_ERROR_BAD_CERTIFICATE:
+            errName.AssignLiteral("SecurityBadCertificateError");
+            break;
+          case SSL_ERROR_UNSUPPORTED_CERTIFICATE_TYPE:
+            errName.AssignLiteral("SecurityUnsupportedCertificateTypeError");
+            break;
+          case SSL_ERROR_UNSUPPORTED_VERSION:
+            errName.AssignLiteral("SecurityUnsupportedTLSVersionError");
+            break;
+          case SSL_ERROR_BAD_CERT_DOMAIN:
+            errName.AssignLiteral("SecurityCertificateDomainMismatchError");
+            break;
+          default:
+            errName.AssignLiteral("SecurityError");
+            break;
+        }
+      }
+    } else {
+      // must be network
+      errorType.AssignLiteral("Network");
+
+      switch (status) {
+        // connect to host:port failed
+        case NS_ERROR_CONNECTION_REFUSED:
+          errName.AssignLiteral("ConnectionRefusedError");
+          break;
+          // network timeout error
+        case NS_ERROR_NET_TIMEOUT:
+          errName.AssignLiteral("NetworkTimeoutError");
+          break;
+          // hostname lookup failed
+        case NS_ERROR_UNKNOWN_HOST:
+          errName.AssignLiteral("DomainNotFoundError");
+          break;
+        case NS_ERROR_NET_INTERRUPT:
+          errName.AssignLiteral("NetworkInterruptError");
+          break;
+        default:
+          errName.AssignLiteral("NetworkError");
+          break;
+      }
+    }
+
+    Unused << NS_WARN_IF(NS_FAILED(FireErrorEvent(errName, errorType, status)));
+  }
+
+  return FireEvent(u"close"_ns);
+}
+
+void TCPSocket::Close() { CloseHelper(true); }
+
+void TCPSocket::CloseImmediately() { CloseHelper(false); }
+
+void TCPSocket::CloseHelper(bool waitForUnsentData) {
+  if (mReadyState == TCPReadyState::Closed ||
+      mReadyState == TCPReadyState::Closing) {
+    return;
+  }
+
+  mReadyState = TCPReadyState::Closing;
+
+  if (mProxyRequest) {
+    mProxyRequest->Cancel(NS_BINDING_ABORTED);
+    mProxyRequest = nullptr;
+  }
+
+  if (mSocketBridgeChild) {
+    mSocketBridgeChild->SendClose();
+    return;
+  }
+
+  if (!mAsyncCopierActive || !waitForUnsentData) {
+    mPendingData.Clear();
+    mPendingDataAfterStartTLS.Clear();
+
+    if (mSocketOutputStream) {
+      mSocketOutputStream->Close();
+      mSocketOutputStream = nullptr;
+    }
+  }
+
+  if (mSocketInputStream) {
+    mSocketInputStream->Close();
+    mSocketInputStream = nullptr;
+  }
+}
+
+bool TCPSocket::Send(const nsACString& aData, mozilla::ErrorResult& aRv) {
+  if (mReadyState != TCPReadyState::Open) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return false;
+  }
+
+  uint64_t byteLength;
+  nsCOMPtr<nsIInputStream> stream;
+  if (mSocketBridgeChild) {
+    mSocketBridgeChild->SendSend(aData);
+    byteLength = aData.Length();
+  } else {
+    nsresult rv = NS_NewCStringInputStream(getter_AddRefs(stream), aData);
+    if (NS_FAILED(rv)) {
+      aRv.Throw(rv);
+      return false;
+    }
+    rv = stream->Available(&byteLength);
+    if (NS_FAILED(rv)) {
+      aRv.Throw(rv);
+      return false;
+    }
+  }
+  return Send(stream, byteLength);
+}
+
+bool TCPSocket::Send(const ArrayBuffer& aData, uint32_t aByteOffset,
+                     const Optional<uint32_t>& aByteLength,
+                     mozilla::ErrorResult& aRv) {
+  if (mReadyState != TCPReadyState::Open) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return false;
+  }
+
+  nsCOMPtr<nsIArrayBufferInputStream> stream;
+
+  aData.ComputeState();
+  uint32_t byteLength =
+      aByteLength.WasPassed() ? aByteLength.Value() : aData.Length();
+
+  if (mSocketBridgeChild) {
+    nsresult rv = mSocketBridgeChild->SendSend(aData, aByteOffset, byteLength);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      aRv.Throw(rv);
+      return false;
+    }
+  } else {
+    JS::Rooted<JS::Value> value(RootingCx(), JS::ObjectValue(*aData.Obj()));
+
+    stream = do_CreateInstance("@mozilla.org/io/arraybuffer-input-stream;1");
+    nsresult rv = stream->SetData(value, aByteOffset, byteLength);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      aRv.Throw(rv);
+      return false;
+    }
+  }
+  return Send(stream, byteLength);
+}
+
+bool TCPSocket::Send(nsIInputStream* aStream, uint32_t aByteLength) {
+  uint64_t newBufferedAmount = BufferedAmount() + aByteLength;
+  bool bufferFull = newBufferedAmount > BUFFER_SIZE;
+  if (bufferFull) {
+    // If we buffered more than some arbitrary amount of data,
+    // (65535 right now) we should tell the caller so they can
+    // wait until ondrain is called if they so desire. Once all the
+    // buffered data has been written to the socket, ondrain is
+    // called.
+    mWaitingForDrain = true;
+  }
+
+  if (mSocketBridgeChild) {
+    // In the child, we just add the buffer length to our bufferedAmount and let
+    // the parent update our bufferedAmount when the data have been sent.
+    mBufferedAmount = newBufferedAmount;
+    return !bufferFull;
+  }
+
+  // This is used to track how many packets we have been told to send. Signaling
+  // this back to the user of this API allows the user to know how many packets
+  // are currently in flight over IPC.
+  ++mTrackingNumber;
+  if (mWaitingForStartTLS) {
+    // When we are waiting for starttls, newStream is added to pendingData
+    // and will be appended to multiplexStream after tls had been set up.
+    mPendingDataAfterStartTLS.AppendElement(aStream);
+  } else {
+    mPendingData.AppendElement(aStream);
+  }
+
+  CalculateBufferedAmount();
+  EnsureCopying();
+
+  return !bufferFull;
+}
+
+TCPReadyState TCPSocket::ReadyState() { return mReadyState; }
+
+TCPSocketBinaryType TCPSocket::BinaryType() const {
+  if (mUseArrayBuffers) {
+    return TCPSocketBinaryType::Arraybuffer;
+  }
+  return TCPSocketBinaryType::String;
+}
+
+already_AddRefed<TCPSocket> TCPSocket::CreateAcceptedSocket(
+    nsIGlobalObject* aGlobal, nsISocketTransport* aTransport,
+    bool aUseArrayBuffers) {
+  RefPtr<TCPSocket> socket =
+      new TCPSocket(aGlobal, u""_ns, 0, false, aUseArrayBuffers);
+  nsresult rv = socket->InitWithTransport(aTransport);
+  NS_ENSURE_SUCCESS(rv, nullptr);
+  return socket.forget();
+}
+
+already_AddRefed<TCPSocket> TCPSocket::CreateAcceptedSocket(
+    nsIGlobalObject* aGlobal, TCPSocketChild* aBridge, bool aUseArrayBuffers) {
+  RefPtr<TCPSocket> socket =
+      new TCPSocket(aGlobal, u""_ns, 0, false, aUseArrayBuffers);
+  socket->InitWithSocketChild(aBridge);
+  return socket.forget();
+}
+
+already_AddRefed<TCPSocket> TCPSocket::Constructor(
+    const GlobalObject& aGlobal, const nsAString& aHost, uint16_t aPort,
+    const SocketOptions& aOptions, mozilla::ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
+  RefPtr<TCPSocket> socket =
+      new TCPSocket(global, aHost, aPort, aOptions.mUseSecureTransport,
+                    aOptions.mBinaryType == TCPSocketBinaryType::Arraybuffer);
+  socket->ResolveProxy();
+
+  return socket.forget();
+}
+
+nsresult TCPSocket::ResolveProxy() {
+  nsresult rv;
+  nsCOMPtr<nsIProtocolProxyService> pps =
+      do_GetService(NS_PROTOCOLPROXYSERVICE_CONTRACTID, &rv);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  nsCString spec = mSsl ? "https://"_ns : "http://"_ns;
+  bool maybeIPv6 = mHost.FindChar(':') != -1;
+  if (maybeIPv6) spec.Append('[');
+  if (!AppendUTF16toUTF8(mHost, spec, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  if (maybeIPv6) spec.Append(']');
+  rv = NS_MutateURI(NS_STANDARDURLMUTATOR_CONTRACTID)
+           .SetSpec(spec)
+           .SetPort(mPort)
+           .Finalize(uri);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIChannel> channel;
+  rv = NS_NewChannel(getter_AddRefs(channel), uri,
+                     nsContentUtils::GetSystemPrincipal(),
+                     nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                     nsIContentPolicy::TYPE_OTHER);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  rv = pps->AsyncResolve(channel,
+                         nsIProtocolProxyService::RESOLVE_PREFER_SOCKS_PROXY,
+                         this, nullptr, getter_AddRefs(mProxyRequest));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::OnProxyAvailable(nsICancelable* aRequest, nsIChannel* aChannel,
+                            nsIProxyInfo* aProxyInfo, nsresult aResult) {
+  mProxyRequest = nullptr;
+  if (NS_SUCCEEDED(aResult) && aProxyInfo) {
+    nsCString proxyType;
+    nsresult rv = aProxyInfo->GetType(proxyType);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      Close();
+      return rv;
+    }
+    // Only supports SOCKS proxy for now.
+    if (proxyType == "socks" || proxyType == "socks4") {
+      return Init(aProxyInfo);
+    }
+  }
+  return Init(nullptr);
+}
+
+nsresult TCPSocket::CreateInputStreamPump() {
+  if (!mSocketInputStream) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+  nsresult rv;
+  mInputStreamPump =
+      do_CreateInstance("@mozilla.org/network/input-stream-pump;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = mInputStreamPump->Init(mSocketInputStream, 0, 0, false, nullptr);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint64_t suspendCount = mSuspendCount;
+  while (suspendCount--) {
+    mInputStreamPump->Suspend();
+  }
+
+  rv = mInputStreamPump->AsyncRead(this);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::OnTransportStatus(nsITransport* aTransport, nsresult aStatus,
+                             int64_t aProgress, int64_t aProgressMax) {
+  if (static_cast<uint32_t>(aStatus) !=
+      static_cast<uint32_t>(nsISocketTransport::STATUS_CONNECTED_TO)) {
+    return NS_OK;
+  }
+
+  mReadyState = TCPReadyState::Open;
+  nsresult rv = CreateInputStreamPump();
+  NS_ENSURE_SUCCESS(rv, rv);
+  FireEvent(u"open"_ns);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::OnInputStreamReady(nsIAsyncInputStream* aStream) {
+  // Only used for detecting if the connection was refused.
+
+  uint64_t dummy;
+  nsresult rv = aStream->Available(&dummy);
+  if (NS_FAILED(rv)) {
+    MaybeReportErrorAndCloseIfOpen(NS_ERROR_CONNECTION_REFUSED);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::OnStartRequest(nsIRequest* aRequest) { return NS_OK; }
+
+NS_IMETHODIMP
+TCPSocket::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aStream,
+                           uint64_t aOffset, uint32_t aCount) {
+  if (mUseArrayBuffers) {
+    nsTArray<uint8_t> buffer;
+    buffer.SetCapacity(aCount);
+    uint32_t actual;
+    nsresult rv = aStream->Read(reinterpret_cast<char*>(buffer.Elements()),
+                                aCount, &actual);
+    NS_ENSURE_SUCCESS(rv, rv);
+    MOZ_ASSERT(actual == aCount);
+    buffer.SetLength(actual);
+
+    if (mSocketBridgeParent) {
+      mSocketBridgeParent->FireArrayBufferDataEvent(buffer, mReadyState);
+      return NS_OK;
+    }
+
+    AutoJSAPI api;
+    if (!api.Init(GetOwnerGlobal())) {
+      return NS_ERROR_FAILURE;
+    }
+    JSContext* cx = api.cx();
+
+    JS::Rooted<JS::Value> value(cx);
+    if (!ToJSValue(cx, TypedArrayCreator<ArrayBuffer>(buffer), &value)) {
+      return NS_ERROR_FAILURE;
+    }
+    FireDataEvent(cx, u"data"_ns, value);
+    return NS_OK;
+  }
+
+  nsCString data;
+  nsresult rv = mInputStreamScriptable->ReadBytes(aCount, data);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (mSocketBridgeParent) {
+    mSocketBridgeParent->FireStringDataEvent(data, mReadyState);
+    return NS_OK;
+  }
+
+  AutoJSAPI api;
+  if (!api.Init(GetOwnerGlobal())) {
+    return NS_ERROR_FAILURE;
+  }
+  JSContext* cx = api.cx();
+
+  JS::Rooted<JS::Value> value(cx);
+  if (!ToJSValue(cx, NS_ConvertASCIItoUTF16(data), &value)) {
+    return NS_ERROR_FAILURE;
+  }
+  FireDataEvent(cx, u"data"_ns, value);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  mInputStreamPump = nullptr;
+
+  if (mAsyncCopierActive && NS_SUCCEEDED(aStatus)) {
+    // If we have some buffered output still, and status is not an
+    // error, the other side has done a half-close, but we don't
+    // want to be in the close state until we are done sending
+    // everything that was buffered. We also don't want to call onclose
+    // yet.
+    return NS_OK;
+  }
+
+  // We call this even if there is no error.
+  MaybeReportErrorAndCloseIfOpen(aStatus);
+  return NS_OK;
+}
+
+void TCPSocket::SetSocketBridgeParent(TCPSocketParent* aBridgeParent) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  mSocketBridgeParent = aBridgeParent;
+}
+
+NS_IMETHODIMP
+TCPSocket::UpdateReadyState(uint32_t aReadyState) {
+  MOZ_ASSERT(mSocketBridgeChild);
+  mReadyState = static_cast<TCPReadyState>(aReadyState);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::UpdateBufferedAmount(uint32_t aBufferedAmount,
+                                uint32_t aTrackingNumber) {
+  if (aTrackingNumber != mTrackingNumber) {
+    return NS_OK;
+  }
+  mBufferedAmount = aBufferedAmount;
+  if (!mBufferedAmount) {
+    if (mWaitingForDrain) {
+      mWaitingForDrain = false;
+      return FireEvent(u"drain"_ns);
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+TCPSocket::Observe(nsISupports* aSubject, const char* aTopic,
+                   const char16_t* aData) {
+  if (!strcmp(aTopic, "inner-window-destroyed")) {
+    nsCOMPtr<nsISupportsPRUint64> wrapper = do_QueryInterface(aSubject);
+    NS_ENSURE_TRUE(wrapper, NS_ERROR_FAILURE);
+    uint64_t innerID;
+    nsresult rv = wrapper->GetData(&innerID);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    if (innerID == mInnerWindowID) {
+      Close();
+    }
+  } else if (!strcmp(aTopic, "profile-change-net-teardown")) {
+    Close();
+  }
+
+  return NS_OK;
+}
+
+/* static */
+bool TCPSocket::ShouldTCPSocketExist(JSContext* aCx, JSObject* aGlobal) {
+  JS::Rooted<JSObject*> global(aCx, aGlobal);
+  return nsContentUtils::ObjectPrincipal(global)->IsSystemPrincipal();
+}
diff --git a/dom/network/TCPSocket.h b/dom/network/TCPSocket.h
new file mode 100644
index 0000000000..a6d807ef54
--- /dev/null
+++ b/dom/network/TCPSocket.h
@@ -0,0 +1,247 @@
+/* -*- 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_dom_TCPSocket_h
+#define mozilla_dom_TCPSocket_h
+
+#include "mozilla/dom/TCPSocketBinding.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/DOMEventTargetHelper.h"
+#include "nsIProxyInfo.h"
+#include "nsITransport.h"
+#include "nsIStreamListener.h"
+#include "nsIAsyncInputStream.h"
+#include "nsISupportsImpl.h"
+#include "nsIObserver.h"
+#include "nsWeakReference.h"
+#include "nsITCPSocketCallback.h"
+#include "nsIProtocolProxyCallback.h"
+#include "js/RootingAPI.h"
+
+class nsISocketTransport;
+class nsIInputStreamPump;
+class nsIScriptableInputStream;
+class nsIBinaryInputStream;
+class nsIMultiplexInputStream;
+class nsIAsyncStreamCopier;
+class nsIInputStream;
+class nsINetworkInfo;
+
+namespace mozilla {
+class ErrorResult;
+namespace dom {
+
+struct ServerSocketOptions;
+class TCPServerSocket;
+class TCPSocketChild;
+class TCPSocketParent;
+
+// This interface is only used for legacy navigator.mozTCPSocket API
+// compatibility.
+class LegacyMozTCPSocket : public nsISupports {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS(LegacyMozTCPSocket)
+
+  explicit LegacyMozTCPSocket(nsPIDOMWindowInner* aWindow);
+
+  already_AddRefed<TCPServerSocket> Listen(uint16_t aPort,
+                                           const ServerSocketOptions& aOptions,
+                                           uint16_t aBacklog, ErrorResult& aRv);
+
+  already_AddRefed<TCPSocket> Open(const nsAString& aHost, uint16_t aPort,
+                                   const SocketOptions& aOptions,
+                                   ErrorResult& aRv);
+
+  bool WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto,
+                  JS::MutableHandle<JSObject*> aReflector);
+
+ private:
+  virtual ~LegacyMozTCPSocket();
+
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+};
+
+class TCPSocket final : public DOMEventTargetHelper,
+                        public nsIStreamListener,
+                        public nsITransportEventSink,
+                        public nsIInputStreamCallback,
+                        public nsIObserver,
+                        public nsSupportsWeakReference,
+                        public nsITCPSocketCallback,
+                        public nsIProtocolProxyCallback {
+ public:
+  TCPSocket(nsIGlobalObject* aGlobal, const nsAString& aHost, uint16_t aPort,
+            bool aSsl, bool aUseArrayBuffers);
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(TCPSocket,
+                                                         DOMEventTargetHelper)
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+  NS_DECL_NSITRANSPORTEVENTSINK
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSITCPSOCKETCALLBACK
+  NS_DECL_NSIPROTOCOLPROXYCALLBACK
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  static bool ShouldTCPSocketExist(JSContext* aCx, JSObject* aGlobal);
+
+  nsISocketTransport* GetTransport() const { return mTransport.get(); }
+
+  void GetHost(nsAString& aHost);
+  uint32_t Port() const;
+  bool Ssl() const;
+  uint64_t BufferedAmount() const { return mBufferedAmount; }
+  void Suspend();
+  void Resume(ErrorResult& aRv);
+  void Close();
+  void CloseImmediately();
+  bool Send(const nsACString& aData, ErrorResult& aRv);
+  bool Send(const ArrayBuffer& aData, uint32_t aByteOffset,
+            const Optional<uint32_t>& aByteLength, ErrorResult& aRv);
+  TCPReadyState ReadyState();
+  TCPSocketBinaryType BinaryType() const;
+  void UpgradeToSecure(ErrorResult& aRv);
+
+  static already_AddRefed<TCPSocket> Constructor(const GlobalObject& aGlobal,
+                                                 const nsAString& aHost,
+                                                 uint16_t aPort,
+                                                 const SocketOptions& aOptions,
+                                                 ErrorResult& aRv);
+
+  // Create a TCPSocket object from an existing low-level socket connection.
+  // Used by the TCPServerSocket implementation when a new connection is
+  // accepted.
+  static already_AddRefed<TCPSocket> CreateAcceptedSocket(
+      nsIGlobalObject* aGlobal, nsISocketTransport* aTransport,
+      bool aUseArrayBuffers);
+  // Create a TCPSocket object from an existing child-side IPC actor.
+  // Used by the TCPServerSocketChild implementation when a new connection is
+  // accepted.
+  static already_AddRefed<TCPSocket> CreateAcceptedSocket(
+      nsIGlobalObject* aGlobal, TCPSocketChild* aBridge, bool aUseArrayBuffers);
+
+  // Initialize this socket's associated IPC actor in the parent process.
+  void SetSocketBridgeParent(TCPSocketParent* aBridgeParent);
+
+  static bool SocketEnabled();
+
+  IMPL_EVENT_HANDLER(open);
+  IMPL_EVENT_HANDLER(drain);
+  IMPL_EVENT_HANDLER(data);
+  IMPL_EVENT_HANDLER(error);
+  IMPL_EVENT_HANDLER(close);
+
+  nsresult Init(nsIProxyInfo* aProxyInfo);
+
+  // Inform this socket that a buffered send() has completed sending.
+  void NotifyCopyComplete(nsresult aStatus);
+
+  // Initialize this socket from a low-level connection that hasn't connected
+  // yet (called from RecvOpenBind() in TCPSocketParent).
+  nsresult InitWithUnconnectedTransport(nsISocketTransport* aTransport);
+
+ private:
+  ~TCPSocket();
+
+  // Initialize this socket with an existing IPC actor.
+  void InitWithSocketChild(TCPSocketChild* aSocketBridge);
+  // Initialize this socket from an existing low-level connection.
+  nsresult InitWithTransport(nsISocketTransport* aTransport);
+  // Initialize the input/output streams for this socket object.
+  nsresult CreateStream();
+  // Initialize the asynchronous read operation from this socket's input stream.
+  nsresult CreateInputStreamPump();
+  // Send the contents of the provided input stream, which is assumed to be the
+  // given length for reporting and buffering purposes.
+  bool Send(nsIInputStream* aStream, uint32_t aByteLength);
+  // Begin an asynchronous copy operation if one is not already in progress.
+  nsresult EnsureCopying();
+  // Re-calculate buffered amount.
+  void CalculateBufferedAmount();
+  // Helper function, should be called by ActivateTLS(), only.
+  void ActivateTLSHelper();
+  // Enable TLS on this socket, dispatch to STSThread if necessary.
+  void ActivateTLS();
+  // Dispatch an error event if necessary, then dispatch a "close" event.
+  nsresult MaybeReportErrorAndCloseIfOpen(nsresult status);
+
+  // Helper for FireDataStringEvent/FireDataArrayEvent.
+  nsresult FireDataEvent(JSContext* aCx, const nsAString& aType,
+                         JS::Handle<JS::Value> aData);
+  // Helper for Close/CloseImmediately
+  void CloseHelper(bool waitForUnsentData);
+
+  nsresult ResolveProxy();
+
+  TCPReadyState mReadyState;
+  // Whether to use strings or array buffers for the "data" event.
+  bool mUseArrayBuffers;
+  nsString mHost;
+  uint16_t mPort;
+  // Whether this socket is using a secure transport.
+  bool mSsl;
+
+  // The associated IPC actor in a child process.
+  RefPtr<TCPSocketChild> mSocketBridgeChild;
+  // The associated IPC actor in a parent process.
+  RefPtr<TCPSocketParent> mSocketBridgeParent;
+
+  // Raw socket streams
+  nsCOMPtr<nsISocketTransport> mTransport;
+  nsCOMPtr<nsIInputStream> mSocketInputStream;
+  nsCOMPtr<nsIOutputStream> mSocketOutputStream;
+
+  nsCOMPtr<nsICancelable> mProxyRequest;
+
+  // Input stream machinery
+  nsCOMPtr<nsIInputStreamPump> mInputStreamPump;
+  nsCOMPtr<nsIScriptableInputStream> mInputStreamScriptable;
+  nsCOMPtr<nsIBinaryInputStream> mInputStreamBinary;
+
+  // Is there an async copy operation in progress?
+  bool mAsyncCopierActive;
+  // True if the buffer is full and a "drain" event is expected by the client.
+  bool mWaitingForDrain;
+
+  // The id of the window that created this socket.
+  uint64_t mInnerWindowID;
+
+  // The current number of buffered bytes. Only used in content processes when
+  // IPC is enabled.
+  uint64_t mBufferedAmount;
+
+  // The number of times this socket has had `Suspend` called without a
+  // corresponding `Resume`.
+  uint32_t mSuspendCount;
+
+  // The current sequence number (ie. number of send operations) that have been
+  // processed. This is used in the IPC scenario by the child process to filter
+  // out outdated notifications about the amount of buffered data present in the
+  // parent process.
+  uint32_t mTrackingNumber;
+
+  // True if this socket has been upgraded to secure after the initial
+  // connection, but the actual upgrade is waiting for an in-progress copy
+  // operation to complete.
+  bool mWaitingForStartTLS;
+  // The buffered data awaiting the TLS upgrade to finish.
+  nsTArray<nsCOMPtr<nsIInputStream>> mPendingDataAfterStartTLS;
+
+  // The data to be sent.
+  nsTArray<nsCOMPtr<nsIInputStream>> mPendingData;
+
+  bool mObserversActive;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_TCPSocket_h
diff --git a/dom/network/TCPSocketChild.cpp b/dom/network/TCPSocketChild.cpp
new file mode 100644
index 0000000000..b6ccba021d
--- /dev/null
+++ b/dom/network/TCPSocketChild.cpp
@@ -0,0 +1,177 @@
+/* -*- 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/. */
+
+#include <algorithm>
+#include "TCPSocketChild.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/Unused.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/dom/PBrowserChild.h"
+#include "mozilla/dom/BrowserChild.h"
+#include "nsITCPSocketCallback.h"
+#include "TCPSocket.h"
+#include "nsContentUtils.h"
+#include "js/ArrayBuffer.h"  // JS::NewArrayBufferWithContents
+#include "js/RootingAPI.h"   // JS::MutableHandle
+#include "js/Utility.h"  // js::ArrayBufferContentsArena, JS::FreePolicy, js_pod_arena_malloc
+#include "js/Value.h"  // JS::Value
+
+using mozilla::net::gNeckoChild;
+
+namespace IPC {
+
+bool DeserializeArrayBuffer(JSContext* cx, const nsTArray<uint8_t>& aBuffer,
+                            JS::MutableHandle<JS::Value> aVal) {
+  mozilla::UniquePtr<uint8_t[], JS::FreePolicy> data(
+      js_pod_arena_malloc<uint8_t>(js::ArrayBufferContentsArena,
+                                   aBuffer.Length()));
+  if (!data) return false;
+  memcpy(data.get(), aBuffer.Elements(), aBuffer.Length());
+
+  JSObject* obj =
+      JS::NewArrayBufferWithContents(cx, aBuffer.Length(), data.get());
+  if (!obj) return false;
+  // If JS::NewArrayBufferWithContents returns non-null, the ownership of
+  // the data is transfered to obj, so we release the ownership here.
+  mozilla::Unused << data.release();
+
+  aVal.setObject(*obj);
+  return true;
+}
+
+}  // namespace IPC
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(TCPSocketChildBase)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(TCPSocketChildBase)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSocket)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(TCPSocketChildBase)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mSocket)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(TCPSocketChildBase)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TCPSocketChildBase)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TCPSocketChildBase)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPSocketChildBase)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+TCPSocketChildBase::TCPSocketChildBase() : mIPCOpen(false) {
+  mozilla::HoldJSObjects(this);
+}
+
+TCPSocketChildBase::~TCPSocketChildBase() { mozilla::DropJSObjects(this); }
+
+NS_IMETHODIMP_(MozExternalRefCountType) TCPSocketChild::Release(void) {
+  nsrefcnt refcnt = TCPSocketChildBase::Release();
+  if (refcnt == 1 && mIPCOpen) {
+    PTCPSocketChild::SendRequestDelete();
+    return 1;
+  }
+  return refcnt;
+}
+
+TCPSocketChild::TCPSocketChild(const nsAString& aHost, const uint16_t& aPort,
+                               nsISerialEventTarget* aTarget)
+    : mHost(aHost), mPort(aPort), mIPCEventTarget(aTarget) {}
+
+void TCPSocketChild::SendOpen(nsITCPSocketCallback* aSocket, bool aUseSSL,
+                              bool aUseArrayBuffers) {
+  mSocket = aSocket;
+
+  AddIPDLReference();
+  gNeckoChild->SendPTCPSocketConstructor(this, mHost, mPort);
+  PTCPSocketChild::SendOpen(mHost, mPort, aUseSSL, aUseArrayBuffers);
+}
+
+void TCPSocketChildBase::ReleaseIPDLReference() {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  mSocket = nullptr;
+  this->Release();
+}
+
+void TCPSocketChildBase::AddIPDLReference() {
+  MOZ_ASSERT(!mIPCOpen);
+  mIPCOpen = true;
+  this->AddRef();
+}
+
+TCPSocketChild::~TCPSocketChild() = default;
+
+mozilla::ipc::IPCResult TCPSocketChild::RecvUpdateBufferedAmount(
+    const uint32_t& aBuffered, const uint32_t& aTrackingNumber) {
+  mSocket->UpdateBufferedAmount(aBuffered, aTrackingNumber);
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketChild::RecvCallback(
+    const nsString& aType, const CallbackData& aData,
+    const uint32_t& aReadyState) {
+  mSocket->UpdateReadyState(aReadyState);
+
+  if (aData.type() == CallbackData::Tvoid_t) {
+    mSocket->FireEvent(aType);
+
+  } else if (aData.type() == CallbackData::TTCPError) {
+    const TCPError& err(aData.get_TCPError());
+    mSocket->FireErrorEvent(err.name(), err.message(), err.errorCode());
+
+  } else if (aData.type() == CallbackData::TSendableData) {
+    const SendableData& data = aData.get_SendableData();
+
+    if (data.type() == SendableData::TArrayOfuint8_t) {
+      mSocket->FireDataArrayEvent(aType, data.get_ArrayOfuint8_t());
+    } else if (data.type() == SendableData::TnsCString) {
+      mSocket->FireDataStringEvent(aType, data.get_nsCString());
+    } else {
+      MOZ_CRASH("Invalid callback data type!");
+    }
+  } else {
+    MOZ_CRASH("Invalid callback type!");
+  }
+  return IPC_OK();
+}
+
+void TCPSocketChild::SendSend(const nsACString& aData) {
+  SendData(nsCString(aData));
+}
+
+nsresult TCPSocketChild::SendSend(const ArrayBuffer& aData,
+                                  uint32_t aByteOffset, uint32_t aByteLength) {
+  uint32_t buflen = aData.Length();
+  uint32_t offset = std::min(buflen, aByteOffset);
+  uint32_t nbytes = std::min(buflen - aByteOffset, aByteLength);
+  FallibleTArray<uint8_t> fallibleArr;
+  if (!fallibleArr.InsertElementsAt(0, aData.Data() + offset, nbytes,
+                                    fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  SendData(SendableData{std::move(fallibleArr)});
+  return NS_OK;
+}
+
+void TCPSocketChild::SetSocket(TCPSocket* aSocket) { mSocket = aSocket; }
+
+void TCPSocketChild::GetHost(nsAString& aHost) { aHost = mHost; }
+
+void TCPSocketChild::GetPort(uint16_t* aPort) const { *aPort = mPort; }
+
+mozilla::ipc::IPCResult TCPSocketChild::RecvRequestDelete() {
+  mozilla::Unused << Send__delete__(this);
+  return IPC_OK();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/network/TCPSocketChild.h b/dom/network/TCPSocketChild.h
new file mode 100644
index 0000000000..b0896d78a3
--- /dev/null
+++ b/dom/network/TCPSocketChild.h
@@ -0,0 +1,77 @@
+/* -*- 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_dom_TCPSocketChild_h
+#define mozilla_dom_TCPSocketChild_h
+
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/net/PTCPSocketChild.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+#include "js/TypeDecls.h"
+
+class nsITCPSocketCallback;
+
+namespace IPC {
+bool DeserializeArrayBuffer(JSContext* cx, const nsTArray<uint8_t>& aBuffer,
+                            JS::MutableHandle<JS::Value> aVal);
+}
+
+namespace mozilla::dom {
+
+class TCPSocket;
+
+class TCPSocketChildBase : public nsISupports {
+ public:
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(TCPSocketChildBase)
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  void AddIPDLReference();
+  void ReleaseIPDLReference();
+
+ protected:
+  TCPSocketChildBase();
+  virtual ~TCPSocketChildBase();
+
+  nsCOMPtr<nsITCPSocketCallback> mSocket;
+  bool mIPCOpen;
+};
+
+class TCPSocketChild : public mozilla::net::PTCPSocketChild,
+                       public TCPSocketChildBase {
+ public:
+  NS_IMETHOD_(MozExternalRefCountType) Release() override;
+
+  TCPSocketChild(const nsAString& aHost, const uint16_t& aPort,
+                 nsISerialEventTarget* aTarget);
+  ~TCPSocketChild();
+
+  void SendOpen(nsITCPSocketCallback* aSocket, bool aUseSSL,
+                bool aUseArrayBuffers);
+  void SendSend(const nsACString& aData);
+  nsresult SendSend(const ArrayBuffer& aData, uint32_t aByteOffset,
+                    uint32_t aByteLength);
+  void SetSocket(TCPSocket* aSocket);
+
+  void GetHost(nsAString& aHost);
+  void GetPort(uint16_t* aPort) const;
+
+  mozilla::ipc::IPCResult RecvCallback(const nsString& aType,
+                                       const CallbackData& aData,
+                                       const uint32_t& aReadyState);
+  mozilla::ipc::IPCResult RecvRequestDelete();
+  mozilla::ipc::IPCResult RecvUpdateBufferedAmount(
+      const uint32_t& aBufferred, const uint32_t& aTrackingNumber);
+
+ private:
+  nsString mHost;
+  uint16_t mPort;
+  nsCOMPtr<nsISerialEventTarget> mIPCEventTarget;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/network/TCPSocketParent.cpp b/dom/network/TCPSocketParent.cpp
new file mode 100644
index 0000000000..dc7bc3c530
--- /dev/null
+++ b/dom/network/TCPSocketParent.cpp
@@ -0,0 +1,223 @@
+/* -*- 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/. */
+
+#include "TCPSocketParent.h"
+#include "jsapi.h"
+#include "jsfriendapi.h"
+#include "nsJSUtils.h"
+#include "mozilla/Unused.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/net/PNeckoParent.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/BrowserParent.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "nsISocketTransport.h"
+#include "nsNetUtil.h"
+#include "TCPSocket.h"
+
+namespace IPC {
+
+// Defined in TCPSocketChild.cpp
+extern bool DeserializeArrayBuffer(JSContext* aCx,
+                                   const nsTArray<uint8_t>& aBuffer,
+                                   JS::MutableHandle<JS::Value> aVal);
+
+}  // namespace IPC
+
+namespace mozilla {
+
+namespace net {
+//
+// set MOZ_LOG=TCPSocket:5
+//
+extern LazyLogModule gTCPSocketLog;
+#define TCPSOCKET_LOG(args) MOZ_LOG(gTCPSocketLog, LogLevel::Debug, args)
+#define TCPSOCKET_LOG_ENABLED() MOZ_LOG_TEST(gTCPSocketLog, LogLevel::Debug)
+}  // namespace net
+
+using namespace net;
+
+namespace dom {
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TCPSocketParentBase)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION(TCPSocketParentBase, mSocket)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(TCPSocketParentBase)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(TCPSocketParentBase)
+
+TCPSocketParentBase::TCPSocketParentBase() : mIPCOpen(false) {}
+
+TCPSocketParentBase::~TCPSocketParentBase() = default;
+
+void TCPSocketParentBase::ReleaseIPDLReference() {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  this->Release();
+}
+
+void TCPSocketParentBase::AddIPDLReference() {
+  MOZ_ASSERT(!mIPCOpen);
+  mIPCOpen = true;
+  this->AddRef();
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType) TCPSocketParent::Release(void) {
+  nsrefcnt refcnt = TCPSocketParentBase::Release();
+  if (refcnt == 1 && mIPCOpen) {
+    mozilla::Unused << PTCPSocketParent::SendRequestDelete();
+    return 1;
+  }
+  return refcnt;
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvOpen(
+    const nsString& aHost, const uint16_t& aPort, const bool& aUseSSL,
+    const bool& aUseArrayBuffers) {
+  mSocket = new TCPSocket(nullptr, aHost, aPort, aUseSSL, aUseArrayBuffers);
+  mSocket->SetSocketBridgeParent(this);
+  NS_ENSURE_SUCCESS(mSocket->Init(nullptr), IPC_OK());
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvStartTLS() {
+  NS_ENSURE_TRUE(mSocket, IPC_OK());
+  ErrorResult rv;
+  mSocket->UpgradeToSecure(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+  }
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvSuspend() {
+  NS_ENSURE_TRUE(mSocket, IPC_OK());
+  mSocket->Suspend();
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvResume() {
+  NS_ENSURE_TRUE(mSocket, IPC_OK());
+  ErrorResult rv;
+  mSocket->Resume(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+  }
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvData(const SendableData& aData) {
+  NS_ENSURE_TRUE(mSocket, IPC_OK());
+  ErrorResult rv;
+
+  switch (aData.type()) {
+    case SendableData::TArrayOfuint8_t: {
+      AutoSafeJSContext autoCx;
+      JS::Rooted<JS::Value> val(autoCx);
+      const nsTArray<uint8_t>& buffer = aData.get_ArrayOfuint8_t();
+      bool ok = IPC::DeserializeArrayBuffer(autoCx, buffer, &val);
+      NS_ENSURE_TRUE(ok, IPC_OK());
+      RootedSpiderMonkeyInterface<ArrayBuffer> data(autoCx);
+      if (!data.Init(&val.toObject())) {
+        TCPSOCKET_LOG(("%s: Failed to allocate memory", __FUNCTION__));
+        return IPC_FAIL_NO_REASON(this);
+      }
+      Optional<uint32_t> byteLength(buffer.Length());
+      mSocket->Send(data, 0, byteLength, rv);
+      break;
+    }
+
+    case SendableData::TnsCString: {
+      const nsCString& strData = aData.get_nsCString();
+      mSocket->Send(strData, rv);
+      break;
+    }
+
+    default:
+      MOZ_CRASH("unexpected SendableData type");
+  }
+  NS_ENSURE_SUCCESS(rv.StealNSResult(), IPC_OK());
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvClose() {
+  NS_ENSURE_TRUE(mSocket, IPC_OK());
+  mSocket->Close();
+  return IPC_OK();
+}
+
+void TCPSocketParent::FireErrorEvent(const nsAString& aName,
+                                     const nsAString& aType, nsresult aError,
+                                     TCPReadyState aReadyState) {
+  SendEvent(u"error"_ns, TCPError(nsString(aName), nsString(aType), aError),
+            aReadyState);
+}
+
+void TCPSocketParent::FireEvent(const nsAString& aType,
+                                TCPReadyState aReadyState) {
+  return SendEvent(aType, mozilla::void_t(), aReadyState);
+}
+
+void TCPSocketParent::FireArrayBufferDataEvent(nsTArray<uint8_t>& aBuffer,
+                                               TCPReadyState aReadyState) {
+  nsTArray<uint8_t> arr = std::move(aBuffer);
+
+  SendableData data(arr);
+  SendEvent(u"data"_ns, data, aReadyState);
+}
+
+void TCPSocketParent::FireStringDataEvent(const nsACString& aData,
+                                          TCPReadyState aReadyState) {
+  SendableData data((nsCString(aData)));
+
+  SendEvent(u"data"_ns, data, aReadyState);
+}
+
+void TCPSocketParent::SendEvent(const nsAString& aType, CallbackData aData,
+                                TCPReadyState aReadyState) {
+  if (mIPCOpen) {
+    mozilla::Unused << PTCPSocketParent::SendCallback(
+        nsString(aType), aData, static_cast<uint32_t>(aReadyState));
+  }
+}
+
+void TCPSocketParent::SetSocket(TCPSocket* socket) { mSocket = socket; }
+
+nsresult TCPSocketParent::GetHost(nsAString& aHost) {
+  if (!mSocket) {
+    NS_ERROR("No internal socket instance mSocket!");
+    return NS_ERROR_FAILURE;
+  }
+  mSocket->GetHost(aHost);
+  return NS_OK;
+}
+
+nsresult TCPSocketParent::GetPort(uint16_t* aPort) {
+  if (!mSocket) {
+    NS_ERROR("No internal socket instance mSocket!");
+    return NS_ERROR_FAILURE;
+  }
+  *aPort = mSocket->Port();
+  return NS_OK;
+}
+
+void TCPSocketParent::ActorDestroy(ActorDestroyReason why) {
+  if (mSocket) {
+    mSocket->Close();
+  }
+  mSocket = nullptr;
+}
+
+mozilla::ipc::IPCResult TCPSocketParent::RecvRequestDelete() {
+  mozilla::Unused << Send__delete__(this);
+  return IPC_OK();
+}
+
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/network/TCPSocketParent.h b/dom/network/TCPSocketParent.h
new file mode 100644
index 0000000000..388add862d
--- /dev/null
+++ b/dom/network/TCPSocketParent.h
@@ -0,0 +1,82 @@
+/* -*- 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_dom_TCPSocketParent_h
+#define mozilla_dom_TCPSocketParent_h
+
+#include "mozilla/dom/TCPSocketBinding.h"
+#include "mozilla/net/PTCPSocketParent.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+#include "js/TypeDecls.h"
+
+#define TCPSOCKETPARENT_CID                          \
+  {                                                  \
+    0x4e7246c6, 0xa8b3, 0x426d, {                    \
+      0x9c, 0x17, 0x76, 0xda, 0xb1, 0xe1, 0xe1, 0x4a \
+    }                                                \
+  }
+
+namespace mozilla::dom {
+
+class TCPSocket;
+
+class TCPSocketParentBase : public nsISupports {
+ public:
+  NS_DECL_CYCLE_COLLECTION_CLASS(TCPSocketParentBase)
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  void AddIPDLReference();
+  void ReleaseIPDLReference();
+
+  bool IPCOpen() const { return mIPCOpen; }
+
+ protected:
+  TCPSocketParentBase();
+  virtual ~TCPSocketParentBase();
+
+  RefPtr<TCPSocket> mSocket;
+  bool mIPCOpen;
+};
+
+class TCPSocketParent : public mozilla::net::PTCPSocketParent,
+                        public TCPSocketParentBase {
+ public:
+  NS_IMETHOD_(MozExternalRefCountType) Release() override;
+
+  TCPSocketParent() = default;
+
+  mozilla::ipc::IPCResult RecvOpen(const nsString& aHost, const uint16_t& aPort,
+                                   const bool& useSSL,
+                                   const bool& aUseArrayBuffers);
+
+  mozilla::ipc::IPCResult RecvStartTLS();
+  mozilla::ipc::IPCResult RecvSuspend();
+  mozilla::ipc::IPCResult RecvResume();
+  mozilla::ipc::IPCResult RecvClose();
+  mozilla::ipc::IPCResult RecvData(const SendableData& aData);
+  mozilla::ipc::IPCResult RecvRequestDelete();
+
+  void FireErrorEvent(const nsAString& aName, const nsAString& aType,
+                      nsresult aError, TCPReadyState aReadyState);
+  void FireEvent(const nsAString& aType, TCPReadyState aReadyState);
+  void FireArrayBufferDataEvent(nsTArray<uint8_t>& aBuffer,
+                                TCPReadyState aReadyState);
+  void FireStringDataEvent(const nsACString& aData, TCPReadyState aReadyState);
+
+  void SetSocket(TCPSocket* socket);
+  nsresult GetHost(nsAString& aHost);
+  nsresult GetPort(uint16_t* aPort);
+
+ private:
+  virtual void ActorDestroy(ActorDestroyReason why) override;
+  void SendEvent(const nsAString& aType, CallbackData aData,
+                 TCPReadyState aReadyState);
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/network/UDPSocket.cpp b/dom/network/UDPSocket.cpp
new file mode 100644
index 0000000000..7639c3b300
--- /dev/null
+++ b/dom/network/UDPSocket.cpp
@@ -0,0 +1,713 @@
+/* -*- 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/. */
+
+#include "UDPSocket.h"
+#include "mozilla/AsyncEventDispatcher.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/ErrorEvent.h"
+#include "mozilla/dom/network/UDPSocketChild.h"
+#include "mozilla/dom/UDPMessageEvent.h"
+#include "mozilla/dom/UDPSocketBinding.h"
+#include "mozilla/dom/UnionTypes.h"
+#include "mozilla/dom/RootedDictionary.h"
+#include "mozilla/net/DNS.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsINetAddr.h"
+#include "nsStringStream.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_ISUPPORTS(UDPSocket::ListenerProxy, nsIUDPSocketListener,
+                  nsIUDPSocketInternal)
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(UDPSocket)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(UDPSocket,
+                                                  DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOpened)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mClosed)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(UDPSocket, DOMEventTargetHelper)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mOpened)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mClosed)
+  tmp->CloseWithReason(NS_OK);
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_ADDREF_INHERITED(UDPSocket, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(UDPSocket, DOMEventTargetHelper)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(UDPSocket)
+  NS_INTERFACE_MAP_ENTRY(nsIUDPSocketListener)
+  NS_INTERFACE_MAP_ENTRY(nsIUDPSocketInternal)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+/* static */
+already_AddRefed<UDPSocket> UDPSocket::Constructor(const GlobalObject& aGlobal,
+                                                   const UDPOptions& aOptions,
+                                                   ErrorResult& aRv) {
+  nsCOMPtr<nsPIDOMWindowInner> ownerWindow =
+      do_QueryInterface(aGlobal.GetAsSupports());
+  if (!ownerWindow) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  bool addressReuse = aOptions.mAddressReuse;
+  bool loopback = aOptions.mLoopback;
+
+  nsCString remoteAddress;
+  if (aOptions.mRemoteAddress.WasPassed()) {
+    CopyUTF16toUTF8(aOptions.mRemoteAddress.Value(), remoteAddress);
+  } else {
+    remoteAddress.SetIsVoid(true);
+  }
+
+  Nullable<uint16_t> remotePort;
+  if (aOptions.mRemotePort.WasPassed()) {
+    remotePort.SetValue(aOptions.mRemotePort.Value());
+
+    if (remotePort.Value() == 0) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+      return nullptr;
+    }
+  }
+
+  nsString localAddress;
+  if (aOptions.mLocalAddress.WasPassed()) {
+    localAddress = aOptions.mLocalAddress.Value();
+
+    // check if localAddress is a valid IPv4/6 address
+    NS_ConvertUTF16toUTF8 address(localAddress);
+    if (!net::HostIsIPLiteral(address)) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+      return nullptr;
+    }
+  } else {
+    SetDOMStringToNull(localAddress);
+  }
+
+  Nullable<uint16_t> localPort;
+  if (aOptions.mLocalPort.WasPassed()) {
+    localPort.SetValue(aOptions.mLocalPort.Value());
+
+    if (localPort.Value() == 0) {
+      aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+      return nullptr;
+    }
+  }
+
+  RefPtr<UDPSocket> socket =
+      new UDPSocket(ownerWindow, remoteAddress, remotePort);
+  aRv = socket->Init(localAddress, localPort, addressReuse, loopback);
+
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return socket.forget();
+}
+
+UDPSocket::UDPSocket(nsPIDOMWindowInner* aOwner,
+                     const nsCString& aRemoteAddress,
+                     const Nullable<uint16_t>& aRemotePort)
+    : DOMEventTargetHelper(aOwner),
+      mRemoteAddress(aRemoteAddress),
+      mRemotePort(aRemotePort),
+      mAddressReuse(false),
+      mLoopback(false),
+      mReadyState(SocketReadyState::Opening) {
+  MOZ_ASSERT(aOwner);
+
+  Document* aDoc = aOwner->GetExtantDoc();
+  if (aDoc) {
+    aDoc->DisallowBFCaching();
+  }
+}
+
+UDPSocket::~UDPSocket() { CloseWithReason(NS_OK); }
+
+JSObject* UDPSocket::WrapObject(JSContext* aCx,
+                                JS::Handle<JSObject*> aGivenProto) {
+  return UDPSocket_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void UDPSocket::DisconnectFromOwner() {
+  DOMEventTargetHelper::DisconnectFromOwner();
+  CloseWithReason(NS_OK);
+}
+
+already_AddRefed<Promise> UDPSocket::Close() {
+  MOZ_ASSERT(mClosed);
+
+  RefPtr<Promise> promise = mClosed;
+
+  if (mReadyState == SocketReadyState::Closed) {
+    return promise.forget();
+  }
+
+  CloseWithReason(NS_OK);
+  return promise.forget();
+}
+
+void UDPSocket::CloseWithReason(nsresult aReason) {
+  if (mReadyState == SocketReadyState::Closed) {
+    return;
+  }
+
+  if (mOpened) {
+    if (mReadyState == SocketReadyState::Opening) {
+      // reject openedPromise with AbortError if socket is closed without error
+      nsresult openFailedReason =
+          NS_FAILED(aReason) ? aReason : NS_ERROR_DOM_ABORT_ERR;
+      mOpened->MaybeReject(openFailedReason);
+    }
+  }
+
+  mReadyState = SocketReadyState::Closed;
+
+  if (mListenerProxy) {
+    mListenerProxy->Disconnect();
+    mListenerProxy = nullptr;
+  }
+
+  if (mSocket) {
+    mSocket->Close();
+    mSocket = nullptr;
+  }
+
+  if (mSocketChild) {
+    mSocketChild->Close();
+    mSocketChild = nullptr;
+  }
+
+  if (mClosed) {
+    if (NS_SUCCEEDED(aReason)) {
+      mClosed->MaybeResolveWithUndefined();
+    } else {
+      mClosed->MaybeReject(aReason);
+    }
+  }
+
+  mPendingMcastCommands.Clear();
+}
+
+void UDPSocket::JoinMulticastGroup(const nsAString& aMulticastGroupAddress,
+                                   ErrorResult& aRv) {
+  if (mReadyState == SocketReadyState::Closed) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  if (mReadyState == SocketReadyState::Opening) {
+    MulticastCommand joinCommand(MulticastCommand::Join,
+                                 aMulticastGroupAddress);
+    mPendingMcastCommands.AppendElement(joinCommand);
+    return;
+  }
+
+  MOZ_ASSERT(mSocket || mSocketChild);
+
+  NS_ConvertUTF16toUTF8 address(aMulticastGroupAddress);
+
+  if (mSocket) {
+    MOZ_ASSERT(!mSocketChild);
+
+    aRv = mSocket->JoinMulticast(address, ""_ns);
+    NS_WARNING_ASSERTION(!aRv.Failed(), "JoinMulticast failed");
+
+    return;
+  }
+
+  MOZ_ASSERT(mSocketChild);
+
+  mSocketChild->JoinMulticast(address, ""_ns);
+}
+
+void UDPSocket::LeaveMulticastGroup(const nsAString& aMulticastGroupAddress,
+                                    ErrorResult& aRv) {
+  if (mReadyState == SocketReadyState::Closed) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  if (mReadyState == SocketReadyState::Opening) {
+    MulticastCommand leaveCommand(MulticastCommand::Leave,
+                                  aMulticastGroupAddress);
+    mPendingMcastCommands.AppendElement(leaveCommand);
+    return;
+  }
+
+  MOZ_ASSERT(mSocket || mSocketChild);
+
+  nsCString address = NS_ConvertUTF16toUTF8(aMulticastGroupAddress);
+  if (mSocket) {
+    MOZ_ASSERT(!mSocketChild);
+
+    aRv = mSocket->LeaveMulticast(address, ""_ns);
+    NS_WARNING_ASSERTION(!aRv.Failed(), "mSocket->LeaveMulticast failed");
+    return;
+  }
+
+  MOZ_ASSERT(mSocketChild);
+
+  mSocketChild->LeaveMulticast(address, ""_ns);
+}
+
+nsresult UDPSocket::DoPendingMcastCommand() {
+  MOZ_ASSERT(mReadyState == SocketReadyState::Open,
+             "Multicast command can only be executed after socket opened");
+
+  for (uint32_t i = 0; i < mPendingMcastCommands.Length(); ++i) {
+    MulticastCommand& command = mPendingMcastCommands[i];
+    ErrorResult rv;
+
+    switch (command.mCommand) {
+      case MulticastCommand::Join: {
+        JoinMulticastGroup(command.mAddress, rv);
+        break;
+      }
+      case MulticastCommand::Leave: {
+        LeaveMulticastGroup(command.mAddress, rv);
+        break;
+      }
+    }
+
+    if (NS_WARN_IF(rv.Failed())) {
+      return rv.StealNSResult();
+    }
+  }
+
+  mPendingMcastCommands.Clear();
+  return NS_OK;
+}
+
+bool UDPSocket::Send(const StringOrBlobOrArrayBufferOrArrayBufferView& aData,
+                     const Optional<nsAString>& aRemoteAddress,
+                     const Optional<Nullable<uint16_t>>& aRemotePort,
+                     ErrorResult& aRv) {
+  if (mReadyState != SocketReadyState::Open) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return false;
+  }
+
+  MOZ_ASSERT(mSocket || mSocketChild);
+
+  // If the remote address and port were not specified in the constructor or as
+  // arguments, throw InvalidAccessError.
+  nsCString remoteAddress;
+  if (aRemoteAddress.WasPassed()) {
+    CopyUTF16toUTF8(aRemoteAddress.Value(), remoteAddress);
+    UDPSOCKET_LOG(("%s: Send to %s", __FUNCTION__, remoteAddress.get()));
+  } else if (!mRemoteAddress.IsVoid()) {
+    remoteAddress = mRemoteAddress;
+    UDPSOCKET_LOG(("%s: Send to %s", __FUNCTION__, remoteAddress.get()));
+  } else {
+    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+    return false;
+  }
+
+  uint16_t remotePort;
+  if (aRemotePort.WasPassed() && !aRemotePort.Value().IsNull()) {
+    remotePort = aRemotePort.Value().Value();
+  } else if (!mRemotePort.IsNull()) {
+    remotePort = mRemotePort.Value();
+  } else {
+    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+    return false;
+  }
+
+  nsCOMPtr<nsIInputStream> stream;
+  if (aData.IsBlob()) {
+    Blob& blob = aData.GetAsBlob();
+
+    blob.CreateInputStream(getter_AddRefs(stream), aRv);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return false;
+    }
+  } else {
+    nsresult rv;
+    nsCOMPtr<nsIStringInputStream> strStream =
+        do_CreateInstance(NS_STRINGINPUTSTREAM_CONTRACTID, &rv);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      aRv.Throw(rv);
+      return false;
+    }
+
+    if (aData.IsString()) {
+      NS_ConvertUTF16toUTF8 data(aData.GetAsString());
+      aRv = strStream->SetData(data.BeginReading(), data.Length());
+    } else if (aData.IsArrayBuffer()) {
+      const ArrayBuffer& data = aData.GetAsArrayBuffer();
+      data.ComputeState();
+      aRv = strStream->SetData(reinterpret_cast<const char*>(data.Data()),
+                               data.Length());
+    } else {
+      const ArrayBufferView& data = aData.GetAsArrayBufferView();
+      data.ComputeState();
+      aRv = strStream->SetData(reinterpret_cast<const char*>(data.Data()),
+                               data.Length());
+    }
+
+    if (NS_WARN_IF(aRv.Failed())) {
+      return false;
+    }
+
+    stream = strStream;
+  }
+
+  if (mSocket) {
+    aRv = mSocket->SendBinaryStream(remoteAddress, remotePort, stream);
+  } else if (mSocketChild) {
+    aRv = mSocketChild->SendBinaryStream(remoteAddress, remotePort, stream);
+  }
+
+  if (NS_WARN_IF(aRv.Failed())) {
+    return false;
+  }
+
+  return true;
+}
+
+nsresult UDPSocket::InitLocal(const nsAString& aLocalAddress,
+                              const uint16_t& aLocalPort) {
+  nsresult rv;
+
+  nsCOMPtr<nsIUDPSocket> sock =
+      do_CreateInstance("@mozilla.org/network/udp-socket;1", &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetOwner(), &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIPrincipal> principal = global->PrincipalOrNull();
+  if (!principal) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (aLocalAddress.IsEmpty()) {
+    rv = sock->Init(aLocalPort, /* loopback = */ false, principal,
+                    mAddressReuse, /* optionalArgc = */ 1);
+  } else {
+    PRNetAddr prAddr;
+    PR_InitializeNetAddr(PR_IpAddrAny, aLocalPort, &prAddr);
+    PR_StringToNetAddr(NS_ConvertUTF16toUTF8(aLocalAddress).BeginReading(),
+                       &prAddr);
+    UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__,
+                   NS_ConvertUTF16toUTF8(aLocalAddress).get(), aLocalPort));
+
+    mozilla::net::NetAddr addr(&prAddr);
+    rv = sock->InitWithAddress(&addr, principal, mAddressReuse,
+                               /* optionalArgc = */ 1);
+  }
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  rv = sock->SetMulticastLoopback(mLoopback);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mSocket = sock;
+
+  // Get real local address and local port
+  nsCOMPtr<nsINetAddr> localAddr;
+  rv = mSocket->GetLocalAddr(getter_AddRefs(localAddr));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCString localAddress;
+  rv = localAddr->GetAddress(localAddress);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  CopyUTF8toUTF16(localAddress, mLocalAddress);
+
+  uint16_t localPort;
+  rv = localAddr->GetPort(&localPort);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mLocalPort.SetValue(localPort);
+
+  mListenerProxy = new ListenerProxy(this);
+
+  rv = mSocket->AsyncListen(mListenerProxy);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mReadyState = SocketReadyState::Open;
+  rv = DoPendingMcastCommand();
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mOpened->MaybeResolveWithUndefined();
+
+  return NS_OK;
+}
+
+nsresult UDPSocket::InitRemote(const nsAString& aLocalAddress,
+                               const uint16_t& aLocalPort) {
+  nsresult rv;
+
+  RefPtr<UDPSocketChild> sock = new UDPSocketChild();
+
+  mListenerProxy = new ListenerProxy(this);
+
+  nsCOMPtr<nsIGlobalObject> obj = do_QueryInterface(GetOwner(), &rv);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsCOMPtr<nsIPrincipal> principal = obj->PrincipalOrNull();
+  if (!principal) {
+    return NS_ERROR_FAILURE;
+  }
+
+  rv = sock->Bind(mListenerProxy, principal,
+                  NS_ConvertUTF16toUTF8(aLocalAddress), aLocalPort,
+                  mAddressReuse, mLoopback, 0, 0);
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  mSocketChild = sock;
+
+  return NS_OK;
+}
+
+nsresult UDPSocket::Init(const nsString& aLocalAddress,
+                         const Nullable<uint16_t>& aLocalPort,
+                         const bool& aAddressReuse, const bool& aLoopback) {
+  MOZ_ASSERT(!mSocket && !mSocketChild);
+
+  mLocalAddress = aLocalAddress;
+  mLocalPort = aLocalPort;
+  mAddressReuse = aAddressReuse;
+  mLoopback = aLoopback;
+
+  ErrorResult rv;
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetOwner());
+
+  mOpened = Promise::Create(global, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return rv.StealNSResult();
+  }
+
+  mClosed = Promise::Create(global, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return rv.StealNSResult();
+  }
+
+  class OpenSocketRunnable final : public Runnable {
+   public:
+    explicit OpenSocketRunnable(UDPSocket* aSocket)
+        : mozilla::Runnable("OpenSocketRunnable"), mSocket(aSocket) {}
+
+    NS_IMETHOD Run() override {
+      MOZ_ASSERT(mSocket);
+
+      if (mSocket->mReadyState != SocketReadyState::Opening) {
+        return NS_OK;
+      }
+
+      uint16_t localPort = 0;
+      if (!mSocket->mLocalPort.IsNull()) {
+        localPort = mSocket->mLocalPort.Value();
+      }
+
+      nsresult rv;
+      if (!XRE_IsParentProcess()) {
+        rv = mSocket->InitRemote(mSocket->mLocalAddress, localPort);
+      } else {
+        rv = mSocket->InitLocal(mSocket->mLocalAddress, localPort);
+      }
+
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        mSocket->CloseWithReason(NS_ERROR_DOM_NETWORK_ERR);
+      }
+
+      return NS_OK;
+    }
+
+   private:
+    RefPtr<UDPSocket> mSocket;
+  };
+
+  nsCOMPtr<nsIRunnable> runnable = new OpenSocketRunnable(this);
+
+  return NS_DispatchToMainThread(runnable);
+}
+
+void UDPSocket::HandleReceivedData(const nsACString& aRemoteAddress,
+                                   const uint16_t& aRemotePort,
+                                   const nsTArray<uint8_t>& aData) {
+  if (mReadyState != SocketReadyState::Open) {
+    return;
+  }
+
+  if (NS_FAILED(CheckCurrentGlobalCorrectness())) {
+    return;
+  }
+
+  if (NS_FAILED(DispatchReceivedData(aRemoteAddress, aRemotePort, aData))) {
+    CloseWithReason(NS_ERROR_UNEXPECTED);
+  }
+}
+
+nsresult UDPSocket::DispatchReceivedData(const nsACString& aRemoteAddress,
+                                         const uint16_t& aRemotePort,
+                                         const nsTArray<uint8_t>& aData) {
+  AutoJSAPI jsapi;
+
+  if (NS_WARN_IF(!jsapi.Init(GetOwner()))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  JSContext* cx = jsapi.cx();
+
+  // Copy packet data to ArrayBuffer
+  JS::Rooted<JSObject*> arrayBuf(
+      cx, ArrayBuffer::Create(cx, aData.Length(), aData.Elements()));
+
+  if (NS_WARN_IF(!arrayBuf)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  JS::Rooted<JS::Value> jsData(cx, JS::ObjectValue(*arrayBuf));
+
+  // Create DOM event
+  RootedDictionary<UDPMessageEventInit> init(cx);
+  CopyUTF8toUTF16(aRemoteAddress, init.mRemoteAddress);
+  init.mRemotePort = aRemotePort;
+  init.mData = jsData;
+
+  RefPtr<UDPMessageEvent> udpEvent =
+      UDPMessageEvent::Constructor(this, u"message"_ns, init);
+
+  if (NS_WARN_IF(!udpEvent)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  udpEvent->SetTrusted(true);
+
+  RefPtr<AsyncEventDispatcher> asyncDispatcher =
+      new AsyncEventDispatcher(this, udpEvent);
+
+  return asyncDispatcher->PostDOMEvent();
+}
+
+// nsIUDPSocketListener
+
+NS_IMETHODIMP
+UDPSocket::OnPacketReceived(nsIUDPSocket* aSocket, nsIUDPMessage* aMessage) {
+  // nsIUDPSocketListener callbacks should be invoked on main thread.
+  MOZ_ASSERT(NS_IsMainThread(), "Not running on main thread");
+
+  // Create appropriate JS object for message
+  FallibleTArray<uint8_t>& buffer = aMessage->GetDataAsTArray();
+
+  nsCOMPtr<nsINetAddr> addr;
+  if (NS_WARN_IF(NS_FAILED(aMessage->GetFromAddr(getter_AddRefs(addr))))) {
+    return NS_OK;
+  }
+
+  nsCString remoteAddress;
+  if (NS_WARN_IF(NS_FAILED(addr->GetAddress(remoteAddress)))) {
+    return NS_OK;
+  }
+
+  uint16_t remotePort;
+  if (NS_WARN_IF(NS_FAILED(addr->GetPort(&remotePort)))) {
+    return NS_OK;
+  }
+
+  HandleReceivedData(remoteAddress, remotePort, buffer);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocket::OnStopListening(nsIUDPSocket* aSocket, nsresult aStatus) {
+  // nsIUDPSocketListener callbacks should be invoked on main thread.
+  MOZ_ASSERT(NS_IsMainThread(), "Not running on main thread");
+
+  CloseWithReason(aStatus);
+
+  return NS_OK;
+}
+
+// nsIUDPSocketInternal
+
+NS_IMETHODIMP
+UDPSocket::CallListenerError(const nsACString& aMessage,
+                             const nsACString& aFilename,
+                             uint32_t aLineNumber) {
+  CloseWithReason(NS_ERROR_DOM_NETWORK_ERR);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocket::CallListenerReceivedData(const nsACString& aRemoteAddress,
+                                    uint16_t aRemotePort,
+                                    const nsTArray<uint8_t>& aData) {
+  HandleReceivedData(aRemoteAddress, aRemotePort, aData);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocket::CallListenerOpened() {
+  if (mReadyState != SocketReadyState::Opening) {
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(mSocketChild);
+
+  // Get real local address and local port
+  CopyUTF8toUTF16(mSocketChild->LocalAddress(), mLocalAddress);
+
+  mLocalPort.SetValue(mSocketChild->LocalPort());
+
+  mReadyState = SocketReadyState::Open;
+  nsresult rv = DoPendingMcastCommand();
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    CloseWithReason(rv);
+    return NS_OK;
+  }
+
+  mOpened->MaybeResolveWithUndefined();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocket::CallListenerConnected() {
+  // This shouldn't be called here.
+  MOZ_CRASH();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocket::CallListenerClosed() {
+  CloseWithReason(NS_OK);
+
+  return NS_OK;
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/network/UDPSocket.h b/dom/network/UDPSocket.h
new file mode 100644
index 0000000000..5453fe5448
--- /dev/null
+++ b/dom/network/UDPSocket.h
@@ -0,0 +1,177 @@
+/* -*- 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_dom_UDPSocket_h__
+#define mozilla_dom_UDPSocket_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/SocketCommonBinding.h"
+#include "nsIUDPSocket.h"
+#include "nsIUDPSocketChild.h"
+#include "nsTArray.h"
+
+struct JSContext;
+
+//
+// set MOZ_LOG=UDPSocket:5
+//
+
+namespace mozilla {
+class ErrorResult;
+class LazyLogModule;
+
+namespace net {
+extern LazyLogModule gUDPSocketLog;
+#define UDPSOCKET_LOG(args) \
+  MOZ_LOG(::mozilla::net::gUDPSocketLog, LogLevel::Debug, args)
+#define UDPSOCKET_LOG_ENABLED() \
+  MOZ_LOG_TEST(::mozilla::net::gUDPSocketLog, LogLevel::Debug)
+}  // namespace net
+
+namespace dom {
+
+struct UDPOptions;
+class StringOrBlobOrArrayBufferOrArrayBufferView;
+class UDPSocketChild;
+
+class UDPSocket final : public DOMEventTargetHelper,
+                        public nsIUDPSocketListener,
+                        public nsIUDPSocketInternal {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(UDPSocket, DOMEventTargetHelper)
+  NS_DECL_NSIUDPSOCKETLISTENER
+  NS_DECL_NSIUDPSOCKETINTERNAL
+
+ public:
+  nsPIDOMWindowInner* GetParentObject() const { return GetOwner(); }
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  virtual void DisconnectFromOwner() override;
+
+  static already_AddRefed<UDPSocket> Constructor(const GlobalObject& aGlobal,
+                                                 const UDPOptions& aOptions,
+                                                 ErrorResult& aRv);
+
+  void GetLocalAddress(nsString& aRetVal) const { aRetVal = mLocalAddress; }
+
+  Nullable<uint16_t> GetLocalPort() const { return mLocalPort; }
+
+  void GetRemoteAddress(nsString& aRetVal) const {
+    if (mRemoteAddress.IsVoid()) {
+      SetDOMStringToNull(aRetVal);
+      return;
+    }
+
+    CopyUTF8toUTF16(mRemoteAddress, aRetVal);
+  }
+
+  Nullable<uint16_t> GetRemotePort() const { return mRemotePort; }
+
+  bool AddressReuse() const { return mAddressReuse; }
+
+  bool Loopback() const { return mLoopback; }
+
+  SocketReadyState ReadyState() const { return mReadyState; }
+
+  Promise* Opened() const { return mOpened; }
+
+  Promise* Closed() const { return mClosed; }
+
+  IMPL_EVENT_HANDLER(message)
+
+  already_AddRefed<Promise> Close();
+
+  void JoinMulticastGroup(const nsAString& aMulticastGroupAddress,
+                          ErrorResult& aRv);
+
+  void LeaveMulticastGroup(const nsAString& aMulticastGroupAddress,
+                           ErrorResult& aRv);
+
+  bool Send(const StringOrBlobOrArrayBufferOrArrayBufferView& aData,
+            const Optional<nsAString>& aRemoteAddress,
+            const Optional<Nullable<uint16_t>>& aRemotePort, ErrorResult& aRv);
+
+ private:
+  class ListenerProxy : public nsIUDPSocketListener,
+                        public nsIUDPSocketInternal {
+   public:
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_SAFE_NSIUDPSOCKETLISTENER(mSocket)
+    NS_FORWARD_SAFE_NSIUDPSOCKETINTERNAL(mSocket)
+
+    explicit ListenerProxy(UDPSocket* aSocket) : mSocket(aSocket) {}
+
+    void Disconnect() { mSocket = nullptr; }
+
+   private:
+    virtual ~ListenerProxy() = default;
+
+    UDPSocket* mSocket;
+  };
+
+  UDPSocket(nsPIDOMWindowInner* aOwner, const nsCString& aRemoteAddress,
+            const Nullable<uint16_t>& aRemotePort);
+
+  virtual ~UDPSocket();
+
+  nsresult Init(const nsString& aLocalAddress,
+                const Nullable<uint16_t>& aLocalPort, const bool& aAddressReuse,
+                const bool& aLoopback);
+
+  nsresult InitLocal(const nsAString& aLocalAddress,
+                     const uint16_t& aLocalPort);
+
+  nsresult InitRemote(const nsAString& aLocalAddress,
+                      const uint16_t& aLocalPort);
+
+  void HandleReceivedData(const nsACString& aRemoteAddress,
+                          const uint16_t& aRemotePort,
+                          const nsTArray<uint8_t>& aData);
+
+  nsresult DispatchReceivedData(const nsACString& aRemoteAddress,
+                                const uint16_t& aRemotePort,
+                                const nsTArray<uint8_t>& aData);
+
+  void CloseWithReason(nsresult aReason);
+
+  nsresult DoPendingMcastCommand();
+
+  nsString mLocalAddress;
+  Nullable<uint16_t> mLocalPort;
+  nsCString mRemoteAddress;
+  Nullable<uint16_t> mRemotePort;
+  bool mAddressReuse;
+  bool mLoopback;
+  SocketReadyState mReadyState;
+  RefPtr<Promise> mOpened;
+  RefPtr<Promise> mClosed;
+
+  nsCOMPtr<nsIUDPSocket> mSocket;
+  RefPtr<UDPSocketChild> mSocketChild;
+  RefPtr<ListenerProxy> mListenerProxy;
+
+  struct MulticastCommand {
+    enum CommandType { Join, Leave };
+
+    MulticastCommand(CommandType aCommand, const nsAString& aAddress)
+        : mCommand(aCommand), mAddress(aAddress) {}
+
+    CommandType mCommand;
+    nsString mAddress;
+  };
+
+  nsTArray<MulticastCommand> mPendingMcastCommands;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_UDPSocket_h__
diff --git a/dom/network/UDPSocketChild.cpp b/dom/network/UDPSocketChild.cpp
new file mode 100644
index 0000000000..e5a09d56dd
--- /dev/null
+++ b/dom/network/UDPSocketChild.cpp
@@ -0,0 +1,234 @@
+/* -*- 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/. */
+
+#include "UDPSocketChild.h"
+#include "UDPSocket.h"
+#include "mozilla/Unused.h"
+#include "mozilla/ipc/IPCStreamUtils.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/PermissionMessageUtils.h"
+#include "mozilla/ipc/BackgroundChild.h"
+#include "mozilla/ipc/PBackgroundChild.h"
+#include "mozilla/ipc/BackgroundUtils.h"
+#include "mozilla/ipc/PBackgroundSharedTypes.h"
+
+using mozilla::net::gNeckoChild;
+
+namespace mozilla::dom {
+
+NS_IMPL_ISUPPORTS(UDPSocketChildBase, nsISupports)
+
+UDPSocketChildBase::UDPSocketChildBase() : mIPCOpen(false) {}
+
+UDPSocketChildBase::~UDPSocketChildBase() = default;
+
+void UDPSocketChildBase::ReleaseIPDLReference() {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  mSocket = nullptr;
+  this->Release();
+}
+
+void UDPSocketChildBase::AddIPDLReference() {
+  MOZ_ASSERT(!mIPCOpen);
+  mIPCOpen = true;
+  this->AddRef();
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType) UDPSocketChild::Release(void) {
+  nsrefcnt refcnt = UDPSocketChildBase::Release();
+  if (refcnt == 1 && mIPCOpen) {
+    PUDPSocketChild::SendRequestDelete();
+    return 1;
+  }
+  return refcnt;
+}
+
+UDPSocketChild::UDPSocketChild() : mBackgroundManager(nullptr), mLocalPort(0) {}
+
+UDPSocketChild::~UDPSocketChild() = default;
+
+nsresult UDPSocketChild::SetBackgroundSpinsEvents() {
+  using mozilla::ipc::BackgroundChild;
+
+  mBackgroundManager = BackgroundChild::GetOrCreateForCurrentThread();
+  if (NS_WARN_IF(!mBackgroundManager)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+nsresult UDPSocketChild::Bind(nsIUDPSocketInternal* aSocket,
+                              nsIPrincipal* aPrincipal, const nsACString& aHost,
+                              uint16_t aPort, bool aAddressReuse,
+                              bool aLoopback, uint32_t recvBufferSize,
+                              uint32_t sendBufferSize) {
+  UDPSOCKET_LOG(
+      ("%s: %s:%u", __FUNCTION__, PromiseFlatCString(aHost).get(), aPort));
+
+  NS_ENSURE_ARG(aSocket);
+
+  if (NS_IsMainThread()) {
+    if (!gNeckoChild->SendPUDPSocketConstructor(this, aPrincipal,
+                                                mFilterName)) {
+      return NS_ERROR_FAILURE;
+    }
+  } else {
+    if (!mBackgroundManager) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+
+    // If we want to support a passed-in principal here we'd need to
+    // convert it to a PrincipalInfo
+    MOZ_ASSERT(!aPrincipal);
+    if (!mBackgroundManager->SendPUDPSocketConstructor(this, Nothing(),
+                                                       mFilterName)) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+
+  mSocket = aSocket;
+  AddIPDLReference();
+
+  SendBind(UDPAddressInfo(nsCString(aHost), aPort), aAddressReuse, aLoopback,
+           recvBufferSize, sendBufferSize);
+  return NS_OK;
+}
+
+void UDPSocketChild::Connect(nsIUDPSocketInternal* aSocket,
+                             const nsACString& aHost, uint16_t aPort) {
+  UDPSOCKET_LOG(
+      ("%s: %s:%u", __FUNCTION__, PromiseFlatCString(aHost).get(), aPort));
+
+  mSocket = aSocket;
+
+  SendConnect(UDPAddressInfo(nsCString(aHost), aPort));
+}
+
+void UDPSocketChild::Close() { SendClose(); }
+
+nsresult UDPSocketChild::SendWithAddress(const NetAddr* aAddr,
+                                         const uint8_t* aData,
+                                         uint32_t aByteLength) {
+  NS_ENSURE_ARG(aAddr);
+  NS_ENSURE_ARG(aData);
+
+  UDPSOCKET_LOG(("%s: %u bytes", __FUNCTION__, aByteLength));
+  return SendDataInternal(UDPSocketAddr(*aAddr), aData, aByteLength);
+}
+
+nsresult UDPSocketChild::SendDataInternal(const UDPSocketAddr& aAddr,
+                                          const uint8_t* aData,
+                                          const uint32_t aByteLength) {
+  NS_ENSURE_ARG(aData);
+
+  FallibleTArray<uint8_t> fallibleArray;
+  if (!fallibleArray.InsertElementsAt(0, aData, aByteLength, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  SendOutgoingData(UDPData{std::move(fallibleArray)}, aAddr);
+
+  return NS_OK;
+}
+
+nsresult UDPSocketChild::SendBinaryStream(const nsACString& aHost,
+                                          uint16_t aPort,
+                                          nsIInputStream* aStream) {
+  NS_ENSURE_ARG(aStream);
+
+  mozilla::ipc::IPCStream stream;
+  if (NS_WARN_IF(!mozilla::ipc::SerializeIPCStream(do_AddRef(aStream), stream,
+                                                   /* aAllowLazy */ false))) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  UDPSOCKET_LOG(
+      ("%s: %s:%u", __FUNCTION__, PromiseFlatCString(aHost).get(), aPort));
+  SendOutgoingData(UDPData(stream),
+                   UDPSocketAddr(UDPAddressInfo(nsCString(aHost), aPort)));
+
+  return NS_OK;
+}
+
+void UDPSocketChild::JoinMulticast(const nsACString& aMulticastAddress,
+                                   const nsACString& aInterface) {
+  SendJoinMulticast(aMulticastAddress, aInterface);
+}
+
+void UDPSocketChild::LeaveMulticast(const nsACString& aMulticastAddress,
+                                    const nsACString& aInterface) {
+  SendLeaveMulticast(aMulticastAddress, aInterface);
+}
+
+nsresult UDPSocketChild::SetFilterName(const nsACString& aFilterName) {
+  if (!mFilterName.IsEmpty()) {
+    // filter name can only be set once.
+    return NS_ERROR_FAILURE;
+  }
+  mFilterName = aFilterName;
+  return NS_OK;
+}
+
+// PUDPSocketChild Methods
+mozilla::ipc::IPCResult UDPSocketChild::RecvCallbackOpened(
+    const UDPAddressInfo& aAddressInfo) {
+  mLocalAddress = aAddressInfo.addr();
+  mLocalPort = aAddressInfo.port();
+
+  UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__, mLocalAddress.get(), mLocalPort));
+  nsresult rv = mSocket->CallListenerOpened();
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+// PUDPSocketChild Methods
+mozilla::ipc::IPCResult UDPSocketChild::RecvCallbackConnected(
+    const UDPAddressInfo& aAddressInfo) {
+  mLocalAddress = aAddressInfo.addr();
+  mLocalPort = aAddressInfo.port();
+
+  UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__, mLocalAddress.get(), mLocalPort));
+  nsresult rv = mSocket->CallListenerConnected();
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketChild::RecvCallbackClosed() {
+  nsresult rv = mSocket->CallListenerClosed();
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketChild::RecvCallbackReceivedData(
+    const UDPAddressInfo& aAddressInfo, nsTArray<uint8_t>&& aData) {
+  UDPSOCKET_LOG(("%s: %s:%u length %zu", __FUNCTION__,
+                 aAddressInfo.addr().get(), aAddressInfo.port(),
+                 aData.Length()));
+  nsresult rv = mSocket->CallListenerReceivedData(aAddressInfo.addr(),
+                                                  aAddressInfo.port(), aData);
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketChild::RecvCallbackError(
+    const nsCString& aMessage, const nsCString& aFilename,
+    const uint32_t& aLineNumber) {
+  UDPSOCKET_LOG(("%s: %s:%s:%u", __FUNCTION__, aMessage.get(), aFilename.get(),
+                 aLineNumber));
+  nsresult rv = mSocket->CallListenerError(aMessage, aFilename, aLineNumber);
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/network/UDPSocketChild.h b/dom/network/UDPSocketChild.h
new file mode 100644
index 0000000000..81e5e39776
--- /dev/null
+++ b/dom/network/UDPSocketChild.h
@@ -0,0 +1,109 @@
+/* -*- 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_dom_UDPSocketChild_h__
+#define mozilla_dom_UDPSocketChild_h__
+
+#include "mozilla/net/PUDPSocketChild.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsCOMPtr.h"
+
+#define UDPSOCKETCHILD_CID                           \
+  {                                                  \
+    0xb47e5a0f, 0xd384, 0x48ef, {                    \
+      0x88, 0x85, 0x42, 0x59, 0x79, 0x3d, 0x9c, 0xf0 \
+    }                                                \
+  }
+
+class nsIInputStream;
+class nsIPrincipal;
+class nsIUDPSocketInternal;
+
+namespace mozilla::dom {
+
+class UDPSocketChildBase : public nsISupports {
+ public:
+  NS_DECL_ISUPPORTS
+
+  void AddIPDLReference();
+  void ReleaseIPDLReference();
+
+ protected:
+  UDPSocketChildBase();
+  virtual ~UDPSocketChildBase();
+  nsCOMPtr<nsIUDPSocketInternal> mSocket;
+  bool mIPCOpen;
+};
+
+class UDPSocketChild : public mozilla::net::PUDPSocketChild,
+                       public UDPSocketChildBase {
+ public:
+  NS_IMETHOD_(MozExternalRefCountType) Release() override;
+
+  UDPSocketChild();
+  virtual ~UDPSocketChild();
+
+  uint16_t LocalPort() const { return mLocalPort; }
+  // Local address as UTF-8.
+  const nsACString& LocalAddress() const { return mLocalAddress; }
+
+  nsresult SetFilterName(const nsACString& aFilterName);
+
+  // Allow hosting this over PBackground instead of PNecko
+  nsresult SetBackgroundSpinsEvents();
+
+  // Tell the chrome process to bind the UDP socket to a given local host and
+  // port
+  nsresult Bind(nsIUDPSocketInternal* aSocket, nsIPrincipal* aPrincipal,
+                const nsACString& aHost, uint16_t aPort, bool aAddressReuse,
+                bool aLoopback, uint32_t recvBufferSize,
+                uint32_t sendBufferSize);
+
+  // Tell the chrome process to connect the UDP socket to a given remote host
+  // and port
+  void Connect(nsIUDPSocketInternal* aSocket, const nsACString& aHost,
+               uint16_t aPort);
+
+  // Send the given data to the given address.
+  nsresult SendWithAddress(const NetAddr* aAddr, const uint8_t* aData,
+                           uint32_t aByteLength);
+
+  // Send input stream. This must be a buffered stream implementation.
+  nsresult SendBinaryStream(const nsACString& aHost, uint16_t aPort,
+                            nsIInputStream* aStream);
+
+  void Close();
+
+  // Address and interface are both UTF-8.
+  void JoinMulticast(const nsACString& aMulticastAddress,
+                     const nsACString& aInterface);
+  void LeaveMulticast(const nsACString& aMulticastAddress,
+                      const nsACString& aInterface);
+
+  mozilla::ipc::IPCResult RecvCallbackOpened(
+      const UDPAddressInfo& aAddressInfo);
+  mozilla::ipc::IPCResult RecvCallbackConnected(
+      const UDPAddressInfo& aAddressInfo);
+  mozilla::ipc::IPCResult RecvCallbackClosed();
+  mozilla::ipc::IPCResult RecvCallbackReceivedData(
+      const UDPAddressInfo& aAddressInfo, nsTArray<uint8_t>&& aData);
+  mozilla::ipc::IPCResult RecvCallbackError(const nsCString& aMessage,
+                                            const nsCString& aFilename,
+                                            const uint32_t& aLineNumber);
+
+ private:
+  nsresult SendDataInternal(const UDPSocketAddr& aAddr, const uint8_t* aData,
+                            const uint32_t aByteLength);
+
+  mozilla::ipc::PBackgroundChild* mBackgroundManager;
+  uint16_t mLocalPort;
+  nsCString mLocalAddress;
+  nsCString mFilterName;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // !defined(mozilla_dom_UDPSocketChild_h__)
diff --git a/dom/network/UDPSocketParent.cpp b/dom/network/UDPSocketParent.cpp
new file mode 100644
index 0000000000..3b7fa190e7
--- /dev/null
+++ b/dom/network/UDPSocketParent.cpp
@@ -0,0 +1,551 @@
+/* -*- 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/. */
+
+#include "UDPSocketParent.h"
+#include "UDPSocket.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIUDPSocket.h"
+#include "nsINetAddr.h"
+#include "nsNetCID.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/ipc/InputStreamUtils.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/net/NeckoCommon.h"
+#include "mozilla/net/PNeckoParent.h"
+#include "nsIPermissionManager.h"
+#include "mozilla/ipc/PBackgroundParent.h"
+#include "transport/runnable_utils.h"
+
+namespace mozilla {
+
+using namespace net;
+
+namespace dom {
+
+NS_IMPL_ISUPPORTS(UDPSocketParent, nsIUDPSocketListener)
+
+UDPSocketParent::UDPSocketParent(PBackgroundParent* aManager)
+    : mBackgroundManager(aManager), mIPCOpen(true) {}
+
+UDPSocketParent::UDPSocketParent(PNeckoParent* aManager)
+    : mBackgroundManager(nullptr), mIPCOpen(true) {}
+
+UDPSocketParent::~UDPSocketParent() = default;
+
+bool UDPSocketParent::Init(nsIPrincipal* aPrincipal,
+                           const nsACString& aFilter) {
+  MOZ_ASSERT_IF(mBackgroundManager, !aPrincipal);
+  // will be used once we move all UDPSocket to PBackground, or
+  // if we add in Principal checking for dom/media/webrtc/transport
+  Unused << mBackgroundManager;
+
+  mPrincipal = aPrincipal;
+
+  if (!aFilter.IsEmpty()) {
+    nsAutoCString contractId(NS_NETWORK_UDP_SOCKET_FILTER_HANDLER_PREFIX);
+    contractId.Append(aFilter);
+    nsCOMPtr<nsISocketFilterHandler> filterHandler =
+        do_GetService(contractId.get());
+    if (filterHandler) {
+      nsresult rv = filterHandler->NewFilter(getter_AddRefs(mFilter));
+      if (NS_FAILED(rv)) {
+        printf_stderr(
+            "Cannot create filter that content specified. "
+            "filter name: %s, error code: %u.",
+            aFilter.BeginReading(), static_cast<uint32_t>(rv));
+        return false;
+      }
+    } else {
+      printf_stderr(
+          "Content doesn't have a valid filter. "
+          "filter name: %s.",
+          aFilter.BeginReading());
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// PUDPSocketParent methods
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvBind(
+    const UDPAddressInfo& aAddressInfo, const bool& aAddressReuse,
+    const bool& aLoopback, const uint32_t& recvBufferSize,
+    const uint32_t& sendBufferSize) {
+  UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__, aAddressInfo.addr().get(),
+                 aAddressInfo.port()));
+
+  if (NS_FAILED(BindInternal(aAddressInfo.addr(), aAddressInfo.port(),
+                             aAddressReuse, aLoopback, recvBufferSize,
+                             sendBufferSize))) {
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  nsCOMPtr<nsINetAddr> localAddr;
+  mSocket->GetLocalAddr(getter_AddRefs(localAddr));
+
+  nsCString addr;
+  if (NS_FAILED(localAddr->GetAddress(addr))) {
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  uint16_t port;
+  if (NS_FAILED(localAddr->GetPort(&port))) {
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  UDPSOCKET_LOG(
+      ("%s: SendCallbackOpened: %s:%u", __FUNCTION__, addr.get(), port));
+  mAddress = {addr, port};
+  mozilla::Unused << SendCallbackOpened(UDPAddressInfo(addr, port));
+
+  return IPC_OK();
+}
+
+nsresult UDPSocketParent::BindInternal(const nsCString& aHost,
+                                       const uint16_t& aPort,
+                                       const bool& aAddressReuse,
+                                       const bool& aLoopback,
+                                       const uint32_t& recvBufferSize,
+                                       const uint32_t& sendBufferSize) {
+  nsresult rv;
+
+  UDPSOCKET_LOG(
+      ("%s: [this=%p] %s:%u addressReuse: %d loopback: %d recvBufferSize: "
+       "%" PRIu32 ", sendBufferSize: %" PRIu32,
+       __FUNCTION__, this, nsCString(aHost).get(), aPort, aAddressReuse,
+       aLoopback, recvBufferSize, sendBufferSize));
+
+  nsCOMPtr<nsIUDPSocket> sock =
+      do_CreateInstance("@mozilla.org/network/udp-socket;1", &rv);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (aHost.IsEmpty()) {
+    rv = sock->Init(aPort, false, mPrincipal, aAddressReuse,
+                    /* optional_argc = */ 1);
+  } else {
+    PRNetAddr prAddr;
+    PR_InitializeNetAddr(PR_IpAddrAny, aPort, &prAddr);
+    PRStatus status = PR_StringToNetAddr(aHost.BeginReading(), &prAddr);
+    if (status != PR_SUCCESS) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mozilla::net::NetAddr addr(&prAddr);
+    rv = sock->InitWithAddress(&addr, mPrincipal, aAddressReuse,
+                               /* optional_argc = */ 1);
+  }
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsINetAddr> laddr;
+  rv = sock->GetLocalAddr(getter_AddRefs(laddr));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  uint16_t family;
+  rv = laddr->GetFamily(&family);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  if (family == nsINetAddr::FAMILY_INET) {
+    rv = sock->SetMulticastLoopback(aLoopback);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+  // TODO: once bug 1252759 is fixed query buffer first and only increase
+  if (recvBufferSize != 0) {
+    rv = sock->SetRecvBufferSize(recvBufferSize);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      UDPSOCKET_LOG(
+          ("%s: [this=%p] %s:%u failed to set recv buffer size to: %" PRIu32,
+           __FUNCTION__, this, nsCString(aHost).get(), aPort, recvBufferSize));
+    }
+  }
+  if (sendBufferSize != 0) {
+    rv = sock->SetSendBufferSize(sendBufferSize);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      UDPSOCKET_LOG(
+          ("%s: [this=%p] %s:%u failed to set send buffer size to: %" PRIu32,
+           __FUNCTION__, this, nsCString(aHost).get(), aPort, sendBufferSize));
+    }
+  }
+
+  // register listener
+  rv = sock->AsyncListen(this);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  mSocket = sock;
+
+  return NS_OK;
+}
+
+static nsCOMPtr<nsIEventTarget> GetSTSThread() {
+  nsresult rv;
+
+  nsCOMPtr<nsIEventTarget> sts_thread;
+
+  sts_thread = do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID, &rv);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+  return sts_thread;
+}
+
+static void CheckSTSThread() {
+  DebugOnly<nsCOMPtr<nsIEventTarget>> sts_thread = GetSTSThread();
+
+  ASSERT_ON_THREAD(sts_thread.value);
+}
+
+// Proxy the Connect() request to the STS thread, since it may block and
+// should be done there.
+mozilla::ipc::IPCResult UDPSocketParent::RecvConnect(
+    const UDPAddressInfo& aAddressInfo) {
+  nsCOMPtr<nsIEventTarget> target = GetCurrentSerialEventTarget();
+  Unused << NS_WARN_IF(NS_FAILED(GetSTSThread()->Dispatch(
+      WrapRunnable(RefPtr<UDPSocketParent>(this), &UDPSocketParent::DoConnect,
+                   mSocket, target, aAddressInfo),
+      NS_DISPATCH_NORMAL)));
+  return IPC_OK();
+}
+
+void UDPSocketParent::DoSendConnectResponse(
+    const UDPAddressInfo& aAddressInfo) {
+  // can't use directly with WrapRunnable due to warnings
+  mozilla::Unused << SendCallbackConnected(aAddressInfo);
+}
+
+void UDPSocketParent::SendConnectResponse(
+    const nsCOMPtr<nsIEventTarget>& aThread,
+    const UDPAddressInfo& aAddressInfo) {
+  Unused << NS_WARN_IF(NS_FAILED(aThread->Dispatch(
+      WrapRunnable(RefPtr<UDPSocketParent>(this),
+                   &UDPSocketParent::DoSendConnectResponse, aAddressInfo),
+      NS_DISPATCH_NORMAL)));
+}
+
+// Runs on STS thread
+void UDPSocketParent::DoConnect(const nsCOMPtr<nsIUDPSocket>& aSocket,
+                                const nsCOMPtr<nsIEventTarget>& aReturnThread,
+                                const UDPAddressInfo& aAddressInfo) {
+  UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__, aAddressInfo.addr().get(),
+                 aAddressInfo.port()));
+  if (NS_FAILED(ConnectInternal(aAddressInfo.addr(), aAddressInfo.port()))) {
+    SendInternalError(aReturnThread, __LINE__);
+    return;
+  }
+  CheckSTSThread();
+
+  nsCOMPtr<nsINetAddr> localAddr;
+  aSocket->GetLocalAddr(getter_AddRefs(localAddr));
+
+  nsCString addr;
+  if (NS_FAILED(localAddr->GetAddress(addr))) {
+    SendInternalError(aReturnThread, __LINE__);
+    return;
+  }
+
+  uint16_t port;
+  if (NS_FAILED(localAddr->GetPort(&port))) {
+    SendInternalError(aReturnThread, __LINE__);
+    return;
+  }
+
+  UDPSOCKET_LOG(
+      ("%s: SendConnectResponse: %s:%u", __FUNCTION__, addr.get(), port));
+  SendConnectResponse(aReturnThread, UDPAddressInfo(addr, port));
+}
+
+nsresult UDPSocketParent::ConnectInternal(const nsCString& aHost,
+                                          const uint16_t& aPort) {
+  nsresult rv;
+
+  UDPSOCKET_LOG(("%s: %s:%u", __FUNCTION__, nsCString(aHost).get(), aPort));
+
+  if (!mSocket) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  PRNetAddr prAddr;
+  memset(&prAddr, 0, sizeof(prAddr));
+  PR_InitializeNetAddr(PR_IpAddrAny, aPort, &prAddr);
+  PRStatus status = PR_StringToNetAddr(aHost.BeginReading(), &prAddr);
+  if (status != PR_SUCCESS) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mozilla::net::NetAddr addr(&prAddr);
+  rv = mSocket->Connect(&addr);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvOutgoingData(
+    const UDPData& aData, const UDPSocketAddr& aAddr) {
+  if (!mSocket) {
+    NS_WARNING("sending socket is closed");
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  nsresult rv;
+  if (mFilter) {
+    if (aAddr.type() != UDPSocketAddr::TNetAddr) {
+      return IPC_OK();
+    }
+
+    // TODO, Packet filter doesn't support input stream yet.
+    if (aData.type() != UDPData::TArrayOfuint8_t) {
+      return IPC_OK();
+    }
+
+    bool allowed;
+    const nsTArray<uint8_t>& data(aData.get_ArrayOfuint8_t());
+    UDPSOCKET_LOG(("%s(%s:%d): Filtering outgoing packet", __FUNCTION__,
+                   mAddress.addr().get(), mAddress.port()));
+
+    rv = mFilter->FilterPacket(&aAddr.get_NetAddr(), data.Elements(),
+                               data.Length(), nsISocketFilter::SF_OUTGOING,
+                               &allowed);
+
+    // Sending unallowed data, kill content.
+    if (NS_WARN_IF(NS_FAILED(rv)) || !allowed) {
+      return IPC_FAIL(this, "Content tried to send non STUN packet");
+    }
+  }
+
+  switch (aData.type()) {
+    case UDPData::TArrayOfuint8_t:
+      Send(aData.get_ArrayOfuint8_t(), aAddr);
+      break;
+    case UDPData::TIPCStream:
+      Send(aData.get_IPCStream(), aAddr);
+      break;
+    default:
+      MOZ_ASSERT(false, "Invalid data type!");
+      return IPC_OK();
+  }
+
+  return IPC_OK();
+}
+
+void UDPSocketParent::Send(const nsTArray<uint8_t>& aData,
+                           const UDPSocketAddr& aAddr) {
+  nsresult rv;
+  uint32_t count;
+  switch (aAddr.type()) {
+    case UDPSocketAddr::TUDPAddressInfo: {
+      const UDPAddressInfo& addrInfo(aAddr.get_UDPAddressInfo());
+      rv = mSocket->Send(addrInfo.addr(), addrInfo.port(), aData, &count);
+      break;
+    }
+    case UDPSocketAddr::TNetAddr: {
+      const NetAddr& addr(aAddr.get_NetAddr());
+      rv = mSocket->SendWithAddress(&addr, aData, &count);
+      break;
+    }
+    default:
+      MOZ_ASSERT(false, "Invalid address type!");
+      return;
+  }
+
+  if (NS_WARN_IF(NS_FAILED(rv)) || count == 0) {
+    FireInternalError(__LINE__);
+  }
+}
+
+void UDPSocketParent::Send(const IPCStream& aStream,
+                           const UDPSocketAddr& aAddr) {
+  nsCOMPtr<nsIInputStream> stream = DeserializeIPCStream(aStream);
+
+  if (NS_WARN_IF(!stream)) {
+    return;
+  }
+
+  nsresult rv;
+  switch (aAddr.type()) {
+    case UDPSocketAddr::TUDPAddressInfo: {
+      const UDPAddressInfo& addrInfo(aAddr.get_UDPAddressInfo());
+      rv = mSocket->SendBinaryStream(addrInfo.addr(), addrInfo.port(), stream);
+      break;
+    }
+    case UDPSocketAddr::TNetAddr: {
+      const NetAddr& addr(aAddr.get_NetAddr());
+      rv = mSocket->SendBinaryStreamWithAddress(&addr, stream);
+      break;
+    }
+    default:
+      MOZ_ASSERT(false, "Invalid address type!");
+      return;
+  }
+
+  if (NS_FAILED(rv)) {
+    FireInternalError(__LINE__);
+  }
+}
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvJoinMulticast(
+    const nsCString& aMulticastAddress, const nsCString& aInterface) {
+  if (!mSocket) {
+    NS_WARNING("multicast socket is closed");
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  nsresult rv = mSocket->JoinMulticast(aMulticastAddress, aInterface);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    FireInternalError(__LINE__);
+  }
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvLeaveMulticast(
+    const nsCString& aMulticastAddress, const nsCString& aInterface) {
+  if (!mSocket) {
+    NS_WARNING("multicast socket is closed");
+    FireInternalError(__LINE__);
+    return IPC_OK();
+  }
+
+  nsresult rv = mSocket->LeaveMulticast(aMulticastAddress, aInterface);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    FireInternalError(__LINE__);
+  }
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvClose() {
+  if (!mSocket) {
+    return IPC_OK();
+  }
+
+  nsresult rv = mSocket->Close();
+  mSocket = nullptr;
+
+  mozilla::Unused << NS_WARN_IF(NS_FAILED(rv));
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult UDPSocketParent::RecvRequestDelete() {
+  mozilla::Unused << Send__delete__(this);
+  return IPC_OK();
+}
+
+void UDPSocketParent::ActorDestroy(ActorDestroyReason why) {
+  MOZ_ASSERT(mIPCOpen);
+  mIPCOpen = false;
+  if (mSocket) {
+    mSocket->Close();
+  }
+  mSocket = nullptr;
+}
+
+// nsIUDPSocketListener
+
+NS_IMETHODIMP
+UDPSocketParent::OnPacketReceived(nsIUDPSocket* aSocket,
+                                  nsIUDPMessage* aMessage) {
+  // receiving packet from remote host, forward the message content to child
+  // process
+  if (!mIPCOpen) {
+    return NS_OK;
+  }
+
+  uint16_t port;
+  nsCString ip;
+  nsCOMPtr<nsINetAddr> fromAddr;
+  aMessage->GetFromAddr(getter_AddRefs(fromAddr));
+  fromAddr->GetPort(&port);
+  fromAddr->GetAddress(ip);
+
+  nsCString data;
+  aMessage->GetData(data);
+
+  const char* buffer = data.get();
+  uint32_t len = data.Length();
+  UDPSOCKET_LOG(("%s: %s:%u, length %u", __FUNCTION__, ip.get(), port, len));
+
+  if (mFilter) {
+    bool allowed;
+    mozilla::net::NetAddr addr;
+    fromAddr->GetNetAddr(&addr);
+    UDPSOCKET_LOG(("%s(%s:%d): Filtering incoming packet", __FUNCTION__,
+                   mAddress.addr().get(), mAddress.port()));
+    nsresult rv = mFilter->FilterPacket(&addr, (const uint8_t*)buffer, len,
+                                        nsISocketFilter::SF_INCOMING, &allowed);
+    // Receiving unallowed data, drop.
+    if (NS_WARN_IF(NS_FAILED(rv)) || !allowed) {
+      if (!allowed) {
+        UDPSOCKET_LOG(("%s: not allowed", __FUNCTION__));
+      }
+      return NS_OK;
+    }
+  }
+
+  FallibleTArray<uint8_t> fallibleArray;
+  if (!fallibleArray.InsertElementsAt(0, buffer, len, fallible)) {
+    FireInternalError(__LINE__);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  nsTArray<uint8_t> infallibleArray{std::move(fallibleArray)};
+
+  // compose callback
+  mozilla::Unused << SendCallbackReceivedData(UDPAddressInfo(ip, port),
+                                              infallibleArray);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+UDPSocketParent::OnStopListening(nsIUDPSocket* aSocket, nsresult aStatus) {
+  // underlying socket is dead, send state update to child process
+  if (mIPCOpen) {
+    mozilla::Unused << SendCallbackClosed();
+  }
+  return NS_OK;
+}
+
+void UDPSocketParent::FireInternalError(uint32_t aLineNo) {
+  if (!mIPCOpen) {
+    return;
+  }
+
+  mozilla::Unused << SendCallbackError("Internal error"_ns,
+                                       nsLiteralCString(__FILE__), aLineNo);
+}
+
+void UDPSocketParent::SendInternalError(const nsCOMPtr<nsIEventTarget>& aThread,
+                                        uint32_t aLineNo) {
+  UDPSOCKET_LOG(("SendInternalError: %u", aLineNo));
+  Unused << NS_WARN_IF(NS_FAILED(aThread->Dispatch(
+      WrapRunnable(RefPtr<UDPSocketParent>(this),
+                   &UDPSocketParent::FireInternalError, aLineNo),
+      NS_DISPATCH_NORMAL)));
+}
+
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/network/UDPSocketParent.h b/dom/network/UDPSocketParent.h
new file mode 100644
index 0000000000..6d4a982bae
--- /dev/null
+++ b/dom/network/UDPSocketParent.h
@@ -0,0 +1,84 @@
+/* -*- 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_dom_UDPSocketParent_h__
+#define mozilla_dom_UDPSocketParent_h__
+
+#include "mozilla/net/PUDPSocketParent.h"
+#include "nsCOMPtr.h"
+#include "nsIUDPSocket.h"
+#include "nsISocketFilter.h"
+#include "mozilla/dom/PermissionMessageUtils.h"
+
+namespace mozilla {
+namespace net {
+class PNeckoParent;
+}  // namespace net
+
+namespace dom {
+
+class UDPSocketParent : public mozilla::net::PUDPSocketParent,
+                        public nsIUDPSocketListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIUDPSOCKETLISTENER
+
+  explicit UDPSocketParent(PBackgroundParent* aManager);
+  explicit UDPSocketParent(PNeckoParent* aManager);
+
+  bool Init(nsIPrincipal* aPrincipal, const nsACString& aFilter);
+
+  mozilla::ipc::IPCResult RecvBind(const UDPAddressInfo& aAddressInfo,
+                                   const bool& aAddressReuse,
+                                   const bool& aLoopback,
+                                   const uint32_t& recvBufferSize,
+                                   const uint32_t& sendBufferSize);
+  mozilla::ipc::IPCResult RecvConnect(const UDPAddressInfo& aAddressInfo);
+  void DoSendConnectResponse(const UDPAddressInfo& aAddressInfo);
+  void SendConnectResponse(const nsCOMPtr<nsIEventTarget>& aThread,
+                           const UDPAddressInfo& aAddressInfo);
+  void DoConnect(const nsCOMPtr<nsIUDPSocket>& aSocket,
+                 const nsCOMPtr<nsIEventTarget>& aReturnThread,
+                 const UDPAddressInfo& aAddressInfo);
+
+  mozilla::ipc::IPCResult RecvOutgoingData(const UDPData& aData,
+                                           const UDPSocketAddr& aAddr);
+
+  mozilla::ipc::IPCResult RecvClose();
+  mozilla::ipc::IPCResult RecvRequestDelete();
+  mozilla::ipc::IPCResult RecvJoinMulticast(const nsCString& aMulticastAddress,
+                                            const nsCString& aInterface);
+  mozilla::ipc::IPCResult RecvLeaveMulticast(const nsCString& aMulticastAddress,
+                                             const nsCString& aInterface);
+
+ private:
+  virtual ~UDPSocketParent();
+
+  virtual void ActorDestroy(ActorDestroyReason why) override;
+  void Send(const nsTArray<uint8_t>& aData, const UDPSocketAddr& aAddr);
+  void Send(const IPCStream& aStream, const UDPSocketAddr& aAddr);
+  nsresult BindInternal(const nsCString& aHost, const uint16_t& aPort,
+                        const bool& aAddressReuse, const bool& aLoopback,
+                        const uint32_t& recvBufferSize,
+                        const uint32_t& sendBufferSize);
+  nsresult ConnectInternal(const nsCString& aHost, const uint16_t& aPort);
+  void FireInternalError(uint32_t aLineNo);
+  void SendInternalError(const nsCOMPtr<nsIEventTarget>& aThread,
+                         uint32_t aLineNo);
+
+  PBackgroundParent* mBackgroundManager;
+
+  bool mIPCOpen;
+  nsCOMPtr<nsIUDPSocket> mSocket;
+  nsCOMPtr<nsISocketFilter> mFilter;
+  nsCOMPtr<nsIPrincipal> mPrincipal;
+  UDPAddressInfo mAddress;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // !defined(mozilla_dom_UDPSocketParent_h__)
diff --git a/dom/network/interfaces/moz.build b/dom/network/interfaces/moz.build
new file mode 100644
index 0000000000..362ad4c228
--- /dev/null
+++ b/dom/network/interfaces/moz.build
@@ -0,0 +1,12 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+XPIDL_SOURCES += [
+    "nsITCPSocketCallback.idl",
+    "nsIUDPSocketChild.idl",
+]
+
+XPIDL_MODULE = "dom_network"
diff --git a/dom/network/interfaces/nsITCPSocketCallback.idl b/dom/network/interfaces/nsITCPSocketCallback.idl
new file mode 100644
index 0000000000..4a2b7a9ef2
--- /dev/null
+++ b/dom/network/interfaces/nsITCPSocketCallback.idl
@@ -0,0 +1,58 @@
+/* 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/. */
+
+/**
+ * MozTCPSocket exposes a TCP client and server sockets
+ * to highly privileged apps. It provides a buffered, non-blocking
+ * interface for sending. For receiving, it uses an asynchronous,
+ * event handler based interface.
+ */
+
+#include "domstubs.idl"
+
+%{C++
+#include "nsTArrayForwardDeclare.h"
+%}
+[ref] native nsUint8TArrayRef(nsTArray<uint8_t>);
+[ptr] native JSContextPtr(JSContext);
+
+
+/*
+ * This interface is implemented in TCPSocket.cpp as an internal interface
+ * for use in cross-process socket implementation.
+ * Needed to account for multiple possible types that can be provided to
+ * the socket callbacks as arguments.
+ */
+[scriptable, uuid(ac2c4b69-cb79-4767-b1ce-bcf62945cd39)]
+interface nsITCPSocketCallback : nsISupports {
+  // Limitation of TCPSocket's buffer size.
+  const unsigned long BUFFER_SIZE = 65536;
+
+  // Dispatch an "error" event at this object with the given name and type.
+  void fireErrorEvent(in AString name, in AString type, in nsresult errorCode);
+
+  // Dispatch a "data" event at this object with a string
+  void fireDataStringEvent(in AString type, in ACString data);
+
+  // Dispatch a "data" event at this object with an Array
+  void fireDataArrayEvent(in AString type, [const] in nsUint8TArrayRef data);
+
+  // Dispatch an event of the given type at this object.
+  void fireEvent(in AString type);
+
+  // Update the DOM object's readyState.
+  // @param readyState
+  //        new ready state
+  void updateReadyState(in unsigned long readystate);
+
+  // Update the DOM object's bufferedAmount value with a tracking number to
+  // to allow tracking of which writes are "in-flight"
+  // @param bufferedAmount
+  //        TCPSocket parent's bufferedAmount.
+  // @param trackingNumber
+  //        A number to ensure the bufferedAmount is updated after data
+  //        from child are sent to parent.
+  void updateBufferedAmount(in uint32_t bufferedAmount,
+                            in uint32_t trackingNumber);
+};
diff --git a/dom/network/interfaces/nsIUDPSocketChild.idl b/dom/network/interfaces/nsIUDPSocketChild.idl
new file mode 100644
index 0000000000..38a8e43576
--- /dev/null
+++ b/dom/network/interfaces/nsIUDPSocketChild.idl
@@ -0,0 +1,30 @@
+/* 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/. */
+
+#include "nsISupports.idl"
+#include "nsINetAddr.idl"
+
+interface nsIUDPSocketInternal;
+interface nsIInputStream;
+interface nsIPrincipal;
+interface nsIEventTarget;
+
+/*
+ * Internal interface for callback from chrome process
+ */
+[scriptable, builtinclass, uuid(613dd3ad-598b-4da9-ad63-bbda50c20098)]
+interface nsIUDPSocketInternal : nsISupports
+{
+  // callback while socket is opened. localPort and localAddress is ready until this time.
+  void callListenerOpened();
+  // callback while socket is connected.
+  void callListenerConnected();
+  // callback while socket is closed.
+  void callListenerClosed();
+  // callback while incoming packet is received.
+  void callListenerReceivedData(in AUTF8String host, in unsigned short port,
+                                in Array<uint8_t> data);
+  // callback while any error happened.
+  void callListenerError(in AUTF8String message, in AUTF8String filename, in uint32_t lineNumber);
+};
diff --git a/dom/network/moz.build b/dom/network/moz.build
new file mode 100644
index 0000000000..c99c91cc1c
--- /dev/null
+++ b/dom/network/moz.build
@@ -0,0 +1,55 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Core", "Networking")
+
+DIRS += ["interfaces"]
+
+MOCHITEST_CHROME_MANIFESTS += ["tests/chrome.ini"]
+MOCHITEST_MANIFESTS += ["tests/mochitest.ini"]
+
+EXPORTS.mozilla.dom += [
+    "TCPServerSocket.h",
+    "TCPSocket.h",
+    "UDPSocket.h",
+]
+
+EXPORTS.mozilla.dom.network += [
+    "Connection.h",
+    "Constants.h",
+    "TCPServerSocketChild.h",
+    "TCPServerSocketParent.h",
+    "TCPSocketChild.h",
+    "TCPSocketParent.h",
+    "UDPSocketChild.h",
+    "UDPSocketParent.h",
+]
+
+UNIFIED_SOURCES += [
+    "Connection.cpp",
+    "ConnectionMainThread.cpp",
+    "ConnectionWorker.cpp",
+    "TCPServerSocket.cpp",
+    "TCPServerSocketChild.cpp",
+    "TCPServerSocketParent.cpp",
+    "TCPSocket.cpp",
+    "TCPSocketChild.cpp",
+    "TCPSocketParent.cpp",
+    "UDPSocket.cpp",
+    "UDPSocketChild.cpp",
+    "UDPSocketParent.cpp",
+]
+
+IPDL_SOURCES += [
+    "PTCPServerSocket.ipdl",
+    "PTCPSocket.ipdl",
+    "PUDPSocket.ipdl",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
diff --git a/dom/network/tests/chrome.ini b/dom/network/tests/chrome.ini
new file mode 100644
index 0000000000..a0b6c2ae3f
--- /dev/null
+++ b/dom/network/tests/chrome.ini
@@ -0,0 +1,11 @@
+[DEFAULT]
+support-files =
+  tcpsocket_test.sys.mjs
+  test_tcpsocket_client_and_server_basics.js
+  file_postMessage_opener.html
+  file_udpsocket_iframe.html
+
+[test_tcpsocket_jsm.html]
+[test_tcpsocket_client_and_server_basics.html]
+[test_tcpsocket_legacy.html]
+[test_udpsocket.html]
diff --git a/dom/network/tests/file_postMessage_opener.html b/dom/network/tests/file_postMessage_opener.html
new file mode 100644
index 0000000000..87359e25c2
--- /dev/null
+++ b/dom/network/tests/file_postMessage_opener.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <script>
+    opener.postMessage("hello", "*");
+  </script>
+</head>
+<body>
+</body>
+</html>
diff --git a/dom/network/tests/file_udpsocket_iframe.html b/dom/network/tests/file_udpsocket_iframe.html
new file mode 100644
index 0000000000..d48e03ee2b
--- /dev/null
+++ b/dom/network/tests/file_udpsocket_iframe.html
@@ -0,0 +1,22 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test UDPSocket BFCache</title>
+</head>
+<body>
+<script type="application/javascript">
+'use strict';
+window.addEventListener('load', function() {
+  let remotePort = parseInt(window.location.search.substring(1), 10);
+  let socket = new UDPSocket();
+  socket.addEventListener('message', function () {
+    socket.send('fail', '127.0.0.1', remotePort);
+  });
+
+  socket.opened.then(function() {
+    socket.send('ready', '127.0.0.1', remotePort);
+  });
+}, {once: true});
+</script>
+</body>
+</html>
diff --git a/dom/network/tests/mochitest.ini b/dom/network/tests/mochitest.ini
new file mode 100644
index 0000000000..3fdb2ebd0a
--- /dev/null
+++ b/dom/network/tests/mochitest.ini
@@ -0,0 +1,9 @@
+[DEFAULT]
+support-files =
+  worker_network_basics.js
+
+[test_network_basics.html]
+skip-if = toolkit == 'android'
+[test_network_basics_worker.html]
+skip-if = toolkit == 'android'
+[test_tcpsocket_not_exposed_to_content.html]
diff --git a/dom/network/tests/tcpsocket_test.sys.mjs b/dom/network/tests/tcpsocket_test.sys.mjs
new file mode 100644
index 0000000000..7a51aced41
--- /dev/null
+++ b/dom/network/tests/tcpsocket_test.sys.mjs
@@ -0,0 +1,12 @@
+export var createSocket = function (host, port, options) {
+  return new TCPSocket(host, port, options);
+};
+
+export var createServer = function (port, options, backlog) {
+  return new TCPServerSocket(port, options, backlog);
+};
+
+// See test_tcpsocket_client_and_server_basics.html's version for rationale.
+export var socketCompartmentInstanceOfArrayBuffer = function (obj) {
+  return obj instanceof ArrayBuffer;
+};
diff --git a/dom/network/tests/test_network_basics.html b/dom/network/tests/test_network_basics.html
new file mode 100644
index 0000000000..e657af916d
--- /dev/null
+++ b/dom/network/tests/test_network_basics.html
@@ -0,0 +1,38 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Network API</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Network Information API **/
+function test() {
+  ok('connection' in navigator, "navigator.connection should exist");
+
+  ok(navigator.connection, "navigator.connection returns an object");
+
+  ok(navigator.connection instanceof EventTarget,
+     "navigator.connection is a EventTarget object");
+
+  ok('type' in navigator.connection,
+     "type should be a Connection attribute");
+  is(navigator.connection.type, "none",
+     "By default connection.type equals to none");
+
+  SimpleTest.finish();
+}
+
+SimpleTest.waitForExplicitFinish();
+SpecialPowers.pushPrefEnv({'set': [["dom.netinfo.enabled", true]]}, test);
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/network/tests/test_network_basics_worker.html b/dom/network/tests/test_network_basics_worker.html
new file mode 100644
index 0000000000..5763ee361b
--- /dev/null
+++ b/dom/network/tests/test_network_basics_worker.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Network in workers API</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Network Information API **/
+function test() {
+  let w = new Worker('worker_network_basics.js');
+  w.onmessage = function(e) {
+    if (e.data.type == 'status') {
+      ok(e.data.status, e.data.msg);
+    } else if (e.data.type == 'finish') {
+      SimpleTest.finish();
+    } else {
+      ok(false, "Unknown message type");
+    }
+  }
+}
+
+SimpleTest.waitForExplicitFinish();
+SpecialPowers.pushPrefEnv({'set': [["dom.netinfo.enabled", true]]}, test);
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/network/tests/test_tcpsocket_client_and_server_basics.html b/dom/network/tests/test_tcpsocket_client_and_server_basics.html
new file mode 100644
index 0000000000..d7e40a4328
--- /dev/null
+++ b/dom/network/tests/test_tcpsocket_client_and_server_basics.html
@@ -0,0 +1,46 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Core tests for TCPSocket and TCPServerSocket that replace their previous
+separate xpcshell incarnations.  This migration and cleanup occurred as part
+of bug 1084245 in order to get coverage of the tests from content.
+
+https://bugzilla.mozilla.org/show_bug.cgi?id=1084245
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1084245</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+  <script type="application/javascript">
+    function createServer(port, options, backlog) {
+      return new TCPServerSocket(port, options, backlog);
+    }
+
+    function createSocket(host, port, options) {
+      return new TCPSocket(host, port, options);
+    }
+
+    // In the JSM case, ArrayBuffers will be created in the compartment of the
+    // JSM with different globals than the
+    // test_tcpsocket_client_and_server_basics.js test logic sees, so we (and
+    // tcpsocket_test.sys.mjs) need to do something.  To avoid complexity relating
+    // to wrappers and the varying nuances of the module scope and global scope
+    // in JSM's (they differ on B2G), we hardcode ArrayBuffer rather than taking
+    // a string that we look up, etc.
+    function socketCompartmentInstanceOfArrayBuffer(obj) {
+      return obj instanceof ArrayBuffer;
+    }
+  </script>
+  <script type="application/javascript" src="test_tcpsocket_client_and_server_basics.js"></script>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1084245">Mozilla Bug 1084245</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+</pre>
+</body>
+</html>
diff --git a/dom/network/tests/test_tcpsocket_client_and_server_basics.js b/dom/network/tests/test_tcpsocket_client_and_server_basics.js
new file mode 100644
index 0000000000..ad653838be
--- /dev/null
+++ b/dom/network/tests/test_tcpsocket_client_and_server_basics.js
@@ -0,0 +1,617 @@
+"use strict";
+
+// These are defined in test_tcpsocket_client_and_server_basics.html
+/* global createServer, createSocket, socketCompartmentInstanceOfArrayBuffer */
+
+// Bug 788960 and later bug 1329245 have taught us that attempting to connect to
+// a port that is not listening or is no longer listening fails to consistently
+// result in the error (or any) event we expect on Darwin/OSX/"OS X".
+const isOSX = Services.appinfo.OS === "Darwin";
+const testConnectingToNonListeningPort = !isOSX;
+
+const SERVER_BACKLOG = -1;
+
+const SOCKET_EVENTS = ["open", "data", "drain", "error", "close"];
+
+function concatUint8Arrays(a, b) {
+  let newArr = new Uint8Array(a.length + b.length);
+  newArr.set(a, 0);
+  newArr.set(b, a.length);
+  return newArr;
+}
+
+function assertUint8ArraysEqual(a, b, comparingWhat) {
+  if (a.length !== b.length) {
+    ok(
+      false,
+      comparingWhat +
+        " arrays do not have the same length; " +
+        a.length +
+        " versus " +
+        b.length
+    );
+    return;
+  }
+  for (let i = 0; i < a.length; i++) {
+    if (a[i] !== b[i]) {
+      ok(
+        false,
+        comparingWhat +
+          " arrays differ at index " +
+          i +
+          a[i] +
+          " versus " +
+          b[i]
+      );
+      return;
+    }
+  }
+  ok(true, comparingWhat + " arrays were equivalent.");
+}
+
+/**
+ * Helper method to add event listeners to a socket and provide two Promise-returning
+ * helpers (see below for docs on them).  This *must* be called during the turn of
+ * the event loop where TCPSocket's constructor is called or the onconnect method is being
+ * invoked.
+ */
+function listenForEventsOnSocket(socket, socketType) {
+  let wantDataLength = null;
+  let wantDataAndClose = false;
+  let pendingResolve = null;
+  let receivedEvents = [];
+  let receivedData = null;
+  let handleGenericEvent = function (event) {
+    dump("(" + socketType + " event: " + event.type + ")\n");
+    if (pendingResolve && wantDataLength === null) {
+      pendingResolve(event);
+      pendingResolve = null;
+    } else {
+      receivedEvents.push(event);
+    }
+  };
+
+  socket.onopen = handleGenericEvent;
+  socket.ondrain = handleGenericEvent;
+  socket.onerror = handleGenericEvent;
+  socket.onclose = function (event) {
+    if (!wantDataAndClose) {
+      handleGenericEvent(event);
+    } else if (pendingResolve) {
+      dump("(" + socketType + " event: close)\n");
+      pendingResolve(receivedData);
+      pendingResolve = null;
+      wantDataAndClose = false;
+    }
+  };
+  socket.ondata = function (event) {
+    dump(
+      "(" +
+        socketType +
+        " event: " +
+        event.type +
+        " length: " +
+        event.data.byteLength +
+        ")\n"
+    );
+    ok(
+      socketCompartmentInstanceOfArrayBuffer(event.data),
+      "payload is ArrayBuffer"
+    );
+    var arr = new Uint8Array(event.data);
+    if (receivedData === null) {
+      receivedData = arr;
+    } else {
+      receivedData = concatUint8Arrays(receivedData, arr);
+    }
+    if (wantDataLength !== null && receivedData.length >= wantDataLength) {
+      pendingResolve(receivedData);
+      pendingResolve = null;
+      receivedData = null;
+      wantDataLength = null;
+    }
+  };
+
+  return {
+    /**
+     * Return a Promise that will be resolved with the next (non-data) event
+     * received by the socket.  If there are queued events, the Promise will
+     * be immediately resolved (but you won't see that until a future turn of
+     * the event loop).
+     */
+    waitForEvent() {
+      if (pendingResolve) {
+        throw new Error("only one wait allowed at a time.");
+      }
+
+      if (receivedEvents.length) {
+        return Promise.resolve(receivedEvents.shift());
+      }
+
+      dump("(" + socketType + " waiting for event)\n");
+      return new Promise(function (resolve, reject) {
+        pendingResolve = resolve;
+      });
+    },
+    /**
+     * Return a Promise that will be resolved with a Uint8Array of at least the
+     * given length.  We buffer / accumulate received data until we have enough
+     * data.  Data is buffered even before you call this method, so be sure to
+     * explicitly wait for any and all data sent by the other side.
+     */
+    waitForDataWithAtLeastLength(length) {
+      if (pendingResolve) {
+        throw new Error("only one wait allowed at a time.");
+      }
+      if (receivedData && receivedData.length >= length) {
+        let promise = Promise.resolve(receivedData);
+        receivedData = null;
+        return promise;
+      }
+      dump("(" + socketType + " waiting for " + length + " bytes)\n");
+      return new Promise(function (resolve, reject) {
+        pendingResolve = resolve;
+        wantDataLength = length;
+      });
+    },
+    waitForAnyDataAndClose() {
+      if (pendingResolve) {
+        throw new Error("only one wait allowed at a time.");
+      }
+
+      return new Promise(function (resolve, reject) {
+        pendingResolve = resolve;
+        // we may receive no data before getting close, in which case we want to
+        // return an empty array
+        receivedData = new Uint8Array();
+        wantDataAndClose = true;
+      });
+    },
+  };
+}
+
+/**
+ * Return a promise that is resolved when the server receives a connection.  The
+ * promise is resolved with { socket, queue } where `queue` is the result of
+ * calling listenForEventsOnSocket(socket).  This must be done because we need
+ * to add the event listener during the connection.
+ */
+function waitForConnection(listeningServer) {
+  return new Promise(function (resolve, reject) {
+    // Because of the event model of sockets, we can't use the
+    // listenForEventsOnSocket mechanism; we need to hook up listeners during
+    // the connect event.
+    listeningServer.onconnect = function (event) {
+      // Clobber the listener to get upset if it receives any more connections
+      // after this.
+      listeningServer.onconnect = function () {
+        ok(false, "Received a connection when not expecting one.");
+      };
+      ok(true, "Listening server accepted socket");
+      resolve({
+        socket: event.socket,
+        queue: listenForEventsOnSocket(event.socket, "server"),
+      });
+    };
+  });
+}
+
+function defer() {
+  var deferred = {};
+  deferred.promise = new Promise(function (resolve, reject) {
+    deferred.resolve = resolve;
+    deferred.reject = reject;
+  });
+  return deferred;
+}
+
+async function test_basics() {
+  // See bug 903830; in e10s mode we never get to find out the localPort if we
+  // let it pick a free port by choosing 0.  This is the same port the xpcshell
+  // test was using.
+  let serverPort = 8085;
+
+  // - Start up a listening socket.
+  let listeningServer = createServer(
+    serverPort,
+    { binaryType: "arraybuffer" },
+    SERVER_BACKLOG
+  );
+
+  let connectedPromise = waitForConnection(listeningServer);
+
+  // -- Open a connection to the server
+  let clientSocket = createSocket("127.0.0.1", serverPort, {
+    binaryType: "arraybuffer",
+  });
+  let clientQueue = listenForEventsOnSocket(clientSocket, "client");
+
+  // (the client connects)
+  is((await clientQueue.waitForEvent()).type, "open", "got open event");
+  is(clientSocket.readyState, "open", "client readyState is open");
+
+  // (the server connected)
+  let { socket: serverSocket, queue: serverQueue } = await connectedPromise;
+  is(serverSocket.readyState, "open", "server readyState is open");
+
+  // -- Simple send / receive
+  // - Send data from client to server
+  // (But not so much we cross the drain threshold.)
+  let smallUint8Array = new Uint8Array(256);
+  for (let i = 0; i < smallUint8Array.length; i++) {
+    smallUint8Array[i] = i;
+  }
+  is(
+    clientSocket.send(smallUint8Array.buffer, 0, smallUint8Array.length),
+    true,
+    "Client sending less than 64k, buffer should not be full."
+  );
+
+  let serverReceived = await serverQueue.waitForDataWithAtLeastLength(256);
+  assertUint8ArraysEqual(
+    serverReceived,
+    smallUint8Array,
+    "Server received/client sent"
+  );
+
+  // - Send data from server to client
+  // (But not so much we cross the drain threshold.)
+  is(
+    serverSocket.send(smallUint8Array.buffer, 0, smallUint8Array.length),
+    true,
+    "Server sending less than 64k, buffer should not be full."
+  );
+
+  let clientReceived = await clientQueue.waitForDataWithAtLeastLength(256);
+  assertUint8ArraysEqual(
+    clientReceived,
+    smallUint8Array,
+    "Client received/server sent"
+  );
+
+  // -- Perform sending multiple times with different buffer slices
+  // - Send data from client to server
+  // (But not so much we cross the drain threshold.)
+  is(
+    clientSocket.send(smallUint8Array.buffer, 0, 7),
+    true,
+    "Client sending less than 64k, buffer should not be full."
+  );
+  is(
+    clientSocket.send(smallUint8Array.buffer, 7, smallUint8Array.length - 7),
+    true,
+    "Client sending less than 64k, buffer should not be full."
+  );
+
+  serverReceived = await serverQueue.waitForDataWithAtLeastLength(256);
+  assertUint8ArraysEqual(
+    serverReceived,
+    smallUint8Array,
+    "Server received/client sent"
+  );
+
+  // - Send data from server to client
+  // (But not so much we cross the drain threshold.)
+  is(
+    serverSocket.send(smallUint8Array.buffer, 0, 7),
+    true,
+    "Server sending less than 64k, buffer should not be full."
+  );
+  is(
+    serverSocket.send(smallUint8Array.buffer, 7, smallUint8Array.length - 7),
+    true,
+    "Server sending less than 64k, buffer should not be full."
+  );
+
+  clientReceived = await clientQueue.waitForDataWithAtLeastLength(256);
+  assertUint8ArraysEqual(
+    clientReceived,
+    smallUint8Array,
+    "Client received/server sent"
+  );
+
+  // -- Send "big" data in both directions
+  // (Enough to cross the buffering/drain threshold; 64KiB)
+  let bigUint8Array = new Uint8Array(65536 + 3);
+  for (let i = 0; i < bigUint8Array.length; i++) {
+    bigUint8Array[i] = i % 256;
+  }
+  // This can be anything from 1 to 65536. The idea is spliting and sending
+  // bigUint8Array in two chunks should trigger ondrain the same as sending
+  // bigUint8Array in one chunk.
+  let lengthOfChunk1 = 65536;
+  is(
+    clientSocket.send(bigUint8Array.buffer, 0, lengthOfChunk1),
+    true,
+    "Client sending chunk1 should not result in the buffer being full."
+  );
+  // Do this twice so we have confidence that the 'drain' event machinery
+  // doesn't break after the first use. The first time we send bigUint8Array in
+  // two chunks, the second time we send bigUint8Array in one chunk.
+  for (let iSend = 0; iSend < 2; iSend++) {
+    // - Send "big" data from the client to the server
+    let offset = iSend == 0 ? lengthOfChunk1 : 0;
+    is(
+      clientSocket.send(bigUint8Array.buffer, offset, bigUint8Array.length),
+      false,
+      "Client sending more than 64k should result in the buffer being full."
+    );
+    is(
+      (await clientQueue.waitForEvent()).type,
+      "drain",
+      "The drain event should fire after a large send that indicated full."
+    );
+
+    serverReceived = await serverQueue.waitForDataWithAtLeastLength(
+      bigUint8Array.length
+    );
+    assertUint8ArraysEqual(
+      serverReceived,
+      bigUint8Array,
+      "server received/client sent"
+    );
+
+    if (iSend == 0) {
+      is(
+        serverSocket.send(bigUint8Array.buffer, 0, lengthOfChunk1),
+        true,
+        "Server sending chunk1 should not result in the buffer being full."
+      );
+    }
+    // - Send "big" data from the server to the client
+    is(
+      serverSocket.send(bigUint8Array.buffer, offset, bigUint8Array.length),
+      false,
+      "Server sending more than 64k should result in the buffer being full."
+    );
+    is(
+      (await serverQueue.waitForEvent()).type,
+      "drain",
+      "The drain event should fire after a large send that indicated full."
+    );
+
+    clientReceived = await clientQueue.waitForDataWithAtLeastLength(
+      bigUint8Array.length
+    );
+    assertUint8ArraysEqual(
+      clientReceived,
+      bigUint8Array,
+      "client received/server sent"
+    );
+  }
+
+  // -- Server closes the connection
+  serverSocket.close();
+  is(
+    serverSocket.readyState,
+    "closing",
+    "readyState should be closing immediately after calling close"
+  );
+
+  is(
+    (await clientQueue.waitForEvent()).type,
+    "close",
+    "The client should get a close event when the server closes."
+  );
+  is(
+    clientSocket.readyState,
+    "closed",
+    "client readyState should be closed after close event"
+  );
+  is(
+    (await serverQueue.waitForEvent()).type,
+    "close",
+    "The server should get a close event when it closes itself."
+  );
+  is(
+    serverSocket.readyState,
+    "closed",
+    "server readyState should be closed after close event"
+  );
+
+  // -- Re-establish connection
+  connectedPromise = waitForConnection(listeningServer);
+  clientSocket = createSocket("127.0.0.1", serverPort, {
+    binaryType: "arraybuffer",
+  });
+  clientQueue = listenForEventsOnSocket(clientSocket, "client");
+  is((await clientQueue.waitForEvent()).type, "open", "got open event");
+
+  let connectedResult = await connectedPromise;
+  // destructuring assignment is not yet ES6 compliant, must manually unpack
+  serverSocket = connectedResult.socket;
+  serverQueue = connectedResult.queue;
+
+  // -- Client closes the connection
+  clientSocket.close();
+  is(
+    clientSocket.readyState,
+    "closing",
+    "client readyState should be losing immediately after calling close"
+  );
+
+  is(
+    (await clientQueue.waitForEvent()).type,
+    "close",
+    "The client should get a close event when it closes itself."
+  );
+  is(
+    clientSocket.readyState,
+    "closed",
+    "client readyState should be closed after the close event is received"
+  );
+  is(
+    (await serverQueue.waitForEvent()).type,
+    "close",
+    "The server should get a close event when the client closes."
+  );
+  is(
+    serverSocket.readyState,
+    "closed",
+    "server readyState should be closed after the close event is received"
+  );
+
+  // -- Re-establish connection
+  connectedPromise = waitForConnection(listeningServer);
+  clientSocket = createSocket("127.0.0.1", serverPort, {
+    binaryType: "arraybuffer",
+  });
+  clientQueue = listenForEventsOnSocket(clientSocket, "client");
+  is((await clientQueue.waitForEvent()).type, "open", "got open event");
+
+  connectedResult = await connectedPromise;
+  // destructuring assignment is not yet ES6 compliant, must manually unpack
+  serverSocket = connectedResult.socket;
+  serverQueue = connectedResult.queue;
+
+  // -- Call close after enqueueing a lot of data, make sure it goes through.
+  // We'll have the client send and close.
+  is(
+    clientSocket.send(bigUint8Array.buffer, 0, bigUint8Array.length),
+    false,
+    "Client sending more than 64k should result in the buffer being full."
+  );
+  clientSocket.close();
+  // The drain will still fire
+  is(
+    (await clientQueue.waitForEvent()).type,
+    "drain",
+    "The drain event should fire after a large send that returned true."
+  );
+  // Then we'll get a close
+  is(
+    (await clientQueue.waitForEvent()).type,
+    "close",
+    "The close event should fire after the drain event."
+  );
+
+  // The server will get its data
+  serverReceived = await serverQueue.waitForDataWithAtLeastLength(
+    bigUint8Array.length
+  );
+  assertUint8ArraysEqual(
+    serverReceived,
+    bigUint8Array,
+    "server received/client sent"
+  );
+  // And a close.
+  is(
+    (await serverQueue.waitForEvent()).type,
+    "close",
+    "The drain event should fire after a large send that returned true."
+  );
+
+  // -- Re-establish connection
+  connectedPromise = waitForConnection(listeningServer);
+  clientSocket = createSocket("127.0.0.1", serverPort, {
+    binaryType: "string",
+  });
+  clientQueue = listenForEventsOnSocket(clientSocket, "client");
+  is((await clientQueue.waitForEvent()).type, "open", "got open event");
+
+  connectedResult = await connectedPromise;
+  // destructuring assignment is not yet ES6 compliant, must manually unpack
+  serverSocket = connectedResult.socket;
+  serverQueue = connectedResult.queue;
+
+  // -- Attempt to send non-string data.
+  // Restore the original behavior by replacing toString with
+  // Object.prototype.toString. (bug 1121938)
+  bigUint8Array.toString = Object.prototype.toString;
+  is(
+    clientSocket.send(bigUint8Array),
+    true,
+    "Client sending a large non-string should only send a small string."
+  );
+  clientSocket.close();
+  // The server will get its data
+  serverReceived = await serverQueue.waitForDataWithAtLeastLength(
+    bigUint8Array.toString().length
+  );
+  // Then we'll get a close
+  is(
+    (await clientQueue.waitForEvent()).type,
+    "close",
+    "The close event should fire after the drain event."
+  );
+
+  // -- Re-establish connection (Test for Close Immediately)
+  connectedPromise = waitForConnection(listeningServer);
+  clientSocket = createSocket("127.0.0.1", serverPort, {
+    binaryType: "arraybuffer",
+  });
+  clientQueue = listenForEventsOnSocket(clientSocket, "client");
+  is((await clientQueue.waitForEvent()).type, "open", "got open event");
+
+  connectedResult = await connectedPromise;
+  // destructuring assignment is not yet ES6 compliant, must manually unpack
+  serverSocket = connectedResult.socket;
+  serverQueue = connectedResult.queue;
+
+  // -- Attempt to send two non-string data.
+  is(
+    clientSocket.send(bigUint8Array.buffer, 0, bigUint8Array.length),
+    false,
+    "Server sending more than 64k should result in the buffer being full."
+  );
+  is(
+    clientSocket.send(bigUint8Array.buffer, 0, bigUint8Array.length),
+    false,
+    "Server sending more than 64k should result in the buffer being full."
+  );
+  clientSocket.closeImmediately();
+
+  serverReceived = await serverQueue.waitForAnyDataAndClose();
+
+  is(
+    serverReceived.length < 2 * bigUint8Array.length,
+    true,
+    "Received array length less than sent array length"
+  );
+
+  // -- Close the listening server (and try to connect)
+  // We want to verify that the server actually closes / stops listening when
+  // we tell it to.
+  listeningServer.close();
+
+  // (We don't run this check on OS X where it's flakey; see definition up top.)
+  if (testConnectingToNonListeningPort) {
+    // - try and connect, get an error
+    clientSocket = createSocket("127.0.0.1", serverPort, {
+      binaryType: "arraybuffer",
+    });
+    clientQueue = listenForEventsOnSocket(clientSocket, "client");
+    is((await clientQueue.waitForEvent()).type, "error", "fail to connect");
+    is(
+      clientSocket.readyState,
+      "closed",
+      "client readyState should be closed after the failure to connect"
+    );
+  }
+}
+
+add_task(test_basics);
+
+/**
+ * Test that TCPSocket works with ipv6 address.
+ */
+add_task(async function test_ipv6() {
+  const { HttpServer } = ChromeUtils.import(
+    "resource://testing-common/httpd.js"
+  );
+  let deferred = defer();
+  let httpServer = new HttpServer();
+  httpServer.start_ipv6(-1);
+
+  let clientSocket = new TCPSocket("::1", httpServer.identity.primaryPort);
+  clientSocket.onopen = () => {
+    ok(true, "Connect to ipv6 address succeeded");
+    deferred.resolve();
+  };
+  clientSocket.onerror = () => {
+    ok(false, "Connect to ipv6 address failed");
+    deferred.reject();
+  };
+  await deferred.promise;
+  await httpServer.stop();
+});
diff --git a/dom/network/tests/test_tcpsocket_jsm.html b/dom/network/tests/test_tcpsocket_jsm.html
new file mode 100644
index 0000000000..026d71ed14
--- /dev/null
+++ b/dom/network/tests/test_tcpsocket_jsm.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for 1207090</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+  <script type="application/javascript">
+    // These are used in the loaded script file.
+    // eslint-disable-next-line no-unused-vars
+    let {
+      createSocket,
+      createServer,
+      socketCompartmentInstanceOfArrayBuffer
+    } = ChromeUtils.importESModule("chrome://mochitests/content/chrome/dom/network/tests/tcpsocket_test.sys.mjs");
+  </script>
+  <script type="application/javascript" src="test_tcpsocket_client_and_server_basics.js"></script>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1207090">Mozilla Bug 1207090</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+</pre>
+<div id="container"></div>
+</body>
+</html>
diff --git a/dom/network/tests/test_tcpsocket_legacy.html b/dom/network/tests/test_tcpsocket_legacy.html
new file mode 100644
index 0000000000..f5c76fb37f
--- /dev/null
+++ b/dom/network/tests/test_tcpsocket_legacy.html
@@ -0,0 +1,57 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+Test of legacy navigator interface for opening TCPSocket/TCPServerSocket.
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 885982</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1084245">Mozilla Bug 1084245</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+</pre>
+<script>
+  SimpleTest.waitForExplicitFinish();
+
+  function runTest() {
+    // See bug 903830; in e10s mode we never get to find out the localPort if we
+    // let it pick a free port by choosing 0.  This is the same port the xpcshell
+    // test was using.
+    var serverPort = 8085;
+
+    var listeningServer = navigator.mozTCPSocket.listen(serverPort,
+                                                        { binaryType: 'arraybuffer' },
+                                                        -1);
+    listeningServer.onconnect = function(ev) {
+      ok(true, "got server connect");
+      listeningServer.close();
+      listeningServer = null;
+      ev.socket.close()
+    }
+
+    var clientSocket = navigator.mozTCPSocket.open('127.0.0.1', serverPort,
+                                                   { binaryType: 'arraybuffer' });
+    clientSocket.onopen = function() { ok(true, "got client open"); }
+    clientSocket.onclose = function() {
+      ok(true, "got client close");
+      clientSocket.close();
+      clientSocket = null;
+      setTimeout(function() {
+        // This just helps the test harness clean up quickly
+        SpecialPowers.forceCC();
+        SpecialPowers.forceGC();
+        SimpleTest.finish();
+      }, 0);
+    }
+  }
+  runTest(); // we used to invoke this as part of a moot pref-setting callback
+</script>
+</body>
+</html>
diff --git a/dom/network/tests/test_tcpsocket_not_exposed_to_content.html b/dom/network/tests/test_tcpsocket_not_exposed_to_content.html
new file mode 100644
index 0000000000..4154eeca5c
--- /dev/null
+++ b/dom/network/tests/test_tcpsocket_not_exposed_to_content.html
@@ -0,0 +1,25 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test to ensure TCPSocket permission enabled and no tcp-socket perm does not allow open</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script type="application/javascript">
+/**
+ * TCPSocket and its legacy mozTCPSocket variant should never be exposed to
+ * content.
+ */
+
+is('TCPSocket' in this, false, "TCPSocket should not be accessible to content");
+is('TCPServerSocket' in this, false, "TCPServerSocket should not be accessible to content");
+is('mozTCPSocket' in navigator, false, "mozTCPSocket should not be accessible to content");
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/network/tests/test_udpsocket.html b/dom/network/tests/test_udpsocket.html
new file mode 100644
index 0000000000..1ca42f2432
--- /dev/null
+++ b/dom/network/tests/test_udpsocket.html
@@ -0,0 +1,403 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test UDPSocket API</title>
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<iframe id="iframe"></iframe>
+<pre id="test">
+<script type="application/javascript">
+'use strict';
+SimpleTest.waitForExplicitFinish();
+SimpleTest.requestFlakyTimeout("untriaged");
+
+const HELLO_WORLD = 'hlo wrld. ';
+const DATA_ARRAY = [0, 255, 254, 0, 1, 2, 3, 0, 255, 255, 254, 0];
+const DATA_ARRAY_BUFFER = new ArrayBuffer(DATA_ARRAY.length);
+const TYPED_DATA_ARRAY = new Uint8Array(DATA_ARRAY_BUFFER);
+const BIG_ARRAY = new Array(4096);
+const BIG_ARRAY_BUFFER = new ArrayBuffer(BIG_ARRAY.length);
+const BIG_TYPED_ARRAY = new Uint8Array(BIG_ARRAY_BUFFER);
+
+for (let i = 0; i < BIG_ARRAY.length; i++) {
+  BIG_ARRAY[i] = Math.floor(Math.random() * 256);
+}
+
+TYPED_DATA_ARRAY.set(DATA_ARRAY);
+BIG_TYPED_ARRAY.set(BIG_ARRAY);
+
+function is_same_buffer(recv_data, expect_data) {
+  let recv_dataview = new Uint8Array(recv_data);
+  let expected_dataview = new Uint8Array(expect_data);
+
+  if (recv_dataview.length !== expected_dataview.length) {
+    return false;
+  }
+
+  for (let i = 0; i < recv_dataview.length; i++) {
+    if (recv_dataview[i] != expected_dataview[i]) {
+      info('discover byte differenct at ' + i);
+      return false;
+    }
+  }
+  return true;
+}
+
+function testOpen() {
+  info('test for creating an UDP Socket');
+  let socket = new UDPSocket();
+  is(socket.localPort, null, 'expect no local port before socket opened');
+  is(socket.localAddress, null, 'expect no local address before socket opened');
+  is(socket.remotePort, null, 'expected no default remote port');
+  is(socket.remoteAddress, null, 'expected no default remote address');
+  is(socket.readyState, 'opening', 'expected ready state = opening');
+  is(socket.loopback, false, 'expected no loopback');
+  is(socket.addressReuse, true, 'expect to reuse address');
+
+  return socket.opened.then(function() {
+    ok(true, 'expect openedPromise to be resolved after successful socket binding');
+    ok(!(socket.localPort === 0), 'expect allocated a local port');
+    is(socket.localAddress, '0.0.0.0', 'expect assigned to default address');
+    is(socket.readyState, 'open', 'expected ready state = open');
+
+    return socket;
+  });
+}
+
+function testSendString(socket) {
+  info('test for sending string data');
+
+  socket.send(HELLO_WORLD, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    socket.addEventListener('message', function(msg) {
+      let recvData= String.fromCharCode.apply(null, new Uint8Array(msg.data));
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      is(recvData, HELLO_WORLD, 'expected same string data');
+      resolve(socket);
+    }, {once: true});
+  });
+}
+
+function testSendArrayBuffer(socket) {
+  info('test for sending ArrayBuffer');
+
+  socket.send(DATA_ARRAY_BUFFER, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    socket.addEventListener('message', function(msg) {
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      ok(is_same_buffer(msg.data, DATA_ARRAY_BUFFER), 'expected same buffer data');
+      resolve(socket);
+    }, {once: true});
+  });
+}
+
+function testSendArrayBufferView(socket) {
+  info('test for sending ArrayBufferView');
+
+  socket.send(TYPED_DATA_ARRAY, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    socket.addEventListener('message', function(msg) {
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      ok(is_same_buffer(msg.data, TYPED_DATA_ARRAY), 'expected same buffer data');
+      resolve(socket);
+    }, {once: true});
+  });
+}
+
+function testSendBlob(socket) {
+  info('test for sending Blob');
+
+  let blob = new Blob([HELLO_WORLD], {type : 'text/plain'});
+  socket.send(blob, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    socket.addEventListener('message', function(msg) {
+      let recvData= String.fromCharCode.apply(null, new Uint8Array(msg.data));
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      is(recvData, HELLO_WORLD, 'expected same string data');
+      resolve(socket);
+    }, {once: true});
+  });
+}
+
+function testSendBigArray(socket) {
+  info('test for sending Big ArrayBuffer');
+
+  socket.send(BIG_TYPED_ARRAY, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    let byteReceived = 0;
+    socket.addEventListener('message', function recv_callback(msg) {
+      let byteBegin = byteReceived;
+      byteReceived += msg.data.byteLength;
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      ok(is_same_buffer(msg.data, BIG_TYPED_ARRAY.subarray(byteBegin, byteReceived)), 'expected same buffer data [' + byteBegin+ '-' + byteReceived + ']');
+      if (byteReceived >= BIG_TYPED_ARRAY.length) {
+        socket.removeEventListener('message', recv_callback);
+        resolve(socket);
+      }
+    });
+  });
+}
+
+function testSendBigBlob(socket) {
+  info('test for sending Big Blob');
+
+  let blob = new Blob([BIG_TYPED_ARRAY]);
+  socket.send(blob, '127.0.0.1', socket.localPort);
+
+  return new Promise(function(resolve, reject) {
+    let byteReceived = 0;
+    socket.addEventListener('message', function recv_callback(msg) {
+      let byteBegin = byteReceived;
+      byteReceived += msg.data.byteLength;
+      is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+      ok(is_same_buffer(msg.data, BIG_TYPED_ARRAY.subarray(byteBegin, byteReceived)), 'expected same buffer data [' + byteBegin+ '-' + byteReceived + ']');
+      if (byteReceived >= BIG_TYPED_ARRAY.length) {
+        socket.removeEventListener('message', recv_callback);
+        resolve(socket);
+      }
+    });
+  });
+}
+
+function testUDPOptions(socket) {
+  info('test for UDP init options');
+
+  let remoteSocket = new UDPSocket({addressReuse: false,
+                                    loopback: true,
+                                    localAddress: '127.0.0.1',
+                                    remoteAddress: '127.0.0.1',
+                                    remotePort: socket.localPort});
+  is(remoteSocket.localAddress, '127.0.0.1', 'expected local address');
+  is(remoteSocket.remoteAddress, '127.0.0.1', 'expected remote address');
+  is(remoteSocket.remotePort, socket.localPort, 'expected remote port');
+  is(remoteSocket.addressReuse, false, 'expected address not reusable');
+  is(remoteSocket.loopback, true, 'expected loopback mode is on');
+
+  return remoteSocket.opened.then(function() {
+    remoteSocket.send(HELLO_WORLD);
+    return new Promise(function(resolve, reject) {
+      socket.addEventListener('message', function(msg) {
+        let recvData= String.fromCharCode.apply(null, new Uint8Array(msg.data));
+        is(msg.remotePort, remoteSocket.localPort, 'expected packet from ' + remoteSocket.localPort);
+        is(recvData, HELLO_WORLD, 'expected same string data');
+        resolve(socket);
+      }, {once: true});
+    });
+  });
+}
+
+function testClose(socket) {
+  info('test for close');
+
+  socket.close();
+  is(socket.readyState, 'closed', 'expect ready state to be "closed"');
+  try {
+    socket.send(HELLO_WORLD, '127.0.0.1', socket.localPort);
+    ok(false, 'unexpect to send successfully');
+  } catch (e) {
+    ok(true, 'expected send fail after socket closed');
+  }
+
+  return socket.closed.then(function() {
+    ok(true, 'expected closedPromise is resolved after socket.close()');
+  });
+}
+
+function testMulticast() {
+  info('test for multicast');
+
+  let socket = new UDPSocket({loopback: true});
+
+  const MCAST_ADDRESS = '224.0.0.255';
+  socket.joinMulticastGroup(MCAST_ADDRESS);
+
+  return socket.opened.then(function() {
+    socket.send(HELLO_WORLD, MCAST_ADDRESS, socket.localPort);
+
+    return new Promise(function(resolve, reject) {
+      socket.addEventListener('message', function(msg) {
+        let recvData= String.fromCharCode.apply(null, new Uint8Array(msg.data));
+        is(msg.remotePort, socket.localPort, 'expected packet from ' + socket.localPort);
+        is(recvData, HELLO_WORLD, 'expected same string data');
+        socket.leaveMulticastGroup(MCAST_ADDRESS);
+        resolve();
+      }, {once: true});
+    });
+  });
+}
+
+function testInvalidUDPOptions() {
+  info('test for invalid UDPOptions');
+  try {
+    new UDPSocket({localAddress: 'not-a-valid-address'});
+    ok(false, 'should not create an UDPSocket with an invalid localAddress');
+  } catch (e) {
+    is(e.name, 'InvalidAccessError', 'expected InvalidAccessError will be thrown if localAddress is not a valid IPv4/6 address');
+  }
+
+  try {
+    new UDPSocket({localPort: 0});
+    ok(false, 'should not create an UDPSocket with an invalid localPort');
+  } catch (e) {
+    is(e.name, 'InvalidAccessError', 'expected InvalidAccessError will be thrown if localPort is not a valid port number');
+  }
+
+  try {
+    new UDPSocket({remotePort: 0});
+    ok(false, 'should not create an UDPSocket with an invalid remotePort');
+  } catch (e) {
+    is(e.name, 'InvalidAccessError', 'expected InvalidAccessError will be thrown if localPort is not a valid port number');
+  }
+}
+
+function testOpenFailed() {
+  info('test for falied on open');
+
+  //according to RFC5737, address block 192.0.2.0/24 should not be used in both local and public contexts
+  let socket = new UDPSocket({localAddress: '192.0.2.0'});
+
+  return socket.opened.then(function() {
+    ok(false, 'should not resolve openedPromise while fail to bind socket');
+    socket.close();
+  }).catch(function(reason) {
+    is(reason.name, 'NetworkError', 'expected openedPromise to be rejected while fail to bind socket');
+  });
+}
+
+function testSendBeforeOpen() {
+  info('test for send before open');
+
+  let socket = new UDPSocket();
+
+  try {
+    socket.send(HELLO_WORLD, '127.0.0.1', 9);
+    ok(false, 'unexpect to send successfully');
+  } catch (e) {
+    ok(true, 'expected send fail before openedPromise is resolved');
+  }
+
+  return socket.opened.then(function() {
+    socket.close();
+  });
+}
+
+function testCloseBeforeOpened() {
+  info('test for close socket before opened');
+
+  let socket = new UDPSocket();
+  socket.opened.then(function() {
+    ok(false, 'should not resolve openedPromise if it has already been closed');
+  }).catch(function(reason) {
+    is(reason.name, 'AbortError', 'expected openedPromise to be rejected while socket is closed during opening');
+  });
+
+  return socket.close().then(function() {
+    ok(true, 'expected closedPromise to be resolved');
+  }).then(socket.opened);
+}
+
+function testOpenWithoutClose() {
+  info('test for open without close');
+
+  let closed = [];
+  for (let i = 0; i < 50; i++) {
+    let socket = new UDPSocket();
+    closed.push(socket.closed);
+  }
+
+  SpecialPowers.gc();
+  info('all unrefereced socket should be closed right after GC');
+
+  return Promise.all(closed);
+}
+
+function awaitEvent(target, event) {
+  return new Promise(resolve => {
+    target.addEventListener(event, resolve, { once: true });
+  });
+}
+
+async function testBFCache() {
+  info('test for bfcache behavior');
+
+  let socket = new UDPSocket();
+
+  await socket.opened;
+
+  let win = window.open(`file_udpsocket_iframe.html?${socket.localPort}`);
+
+  let msg = await awaitEvent(socket, "message");
+
+  win.location = "file_postMessage_opener.html";
+  await awaitEvent(window, "message");
+
+  socket.send(HELLO_WORLD, '127.0.0.1', msg.remotePort);
+
+  await new Promise(resolve => {
+    function recv_again_callback(message) {
+      socket.removeEventListener('message', recv_again_callback);
+      ok(false, 'should not receive packet after page unload');
+    }
+
+    socket.addEventListener('message', recv_again_callback);
+
+    setTimeout(function() {
+      socket.removeEventListener('message', recv_again_callback);
+      socket.close();
+      resolve();
+    }, 5000);
+  });
+
+  win.close();
+}
+
+function runTest() {
+  testOpen()
+  .then(testSendString)
+  .then(testSendArrayBuffer)
+  .then(testSendArrayBufferView)
+  .then(testSendBlob)
+  .then(testSendBigArray)
+  .then(testSendBigBlob)
+  .then(testUDPOptions)
+  .then(testClose)
+  .then(testMulticast)
+  .then(testInvalidUDPOptions)
+  .then(testOpenFailed)
+  .then(testSendBeforeOpen)
+  .then(testCloseBeforeOpened)
+  .then(testOpenWithoutClose)
+  .then(testBFCache)
+  .then(function() {
+    info('test finished');
+    SimpleTest.finish();
+  })
+  .catch(function(err) {
+    ok(false, 'test failed due to: ' + err);
+    SimpleTest.finish();
+  });
+}
+
+window.addEventListener('load', function () {
+  SpecialPowers.pushPrefEnv({
+    'set': [
+      ['dom.udpsocket.enabled', true],
+      ['browser.sessionhistory.max_total_viewers', 10]
+    ]
+  }, runTest);
+});
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/network/tests/worker_network_basics.js b/dom/network/tests/worker_network_basics.js
new file mode 100644
index 0000000000..25e8c5dd8e
--- /dev/null
+++ b/dom/network/tests/worker_network_basics.js
@@ -0,0 +1,28 @@
+function ok(a, msg) {
+  postMessage({ type: "status", status: !!a, msg });
+}
+
+function is(a, b, msg) {
+  ok(a === b, msg);
+}
+
+function finish() {
+  postMessage({ type: "finish" });
+}
+
+ok("connection" in navigator, "navigator.connection should exist");
+
+ok(navigator.connection, "navigator.connection returns an object");
+
+ok(
+  navigator.connection instanceof EventTarget,
+  "navigator.connection is a EventTarget object"
+);
+
+ok("type" in navigator.connection, "type should be a Connection attribute");
+is(
+  navigator.connection.type,
+  "none",
+  "By default connection.type equals to none"
+);
+finish();