Add m-esr52 at 52.6.0

22 files changed, 4580 insertions, 0 deletions

diff --git a/netwerk/dns/mdns/libmdns/MDNSResponderOperator.cpp b/netwerk/dns/mdns/libmdns/MDNSResponderOperator.cpp
new file mode 100644
index 000000000..72b557774
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/MDNSResponderOperator.cpp
@@ -0,0 +1,779 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "MDNSResponderOperator.h"
+#include "MDNSResponderReply.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/Logging.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Unused.h"
+#include "nsComponentManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsDNSServiceInfo.h"
+#include "nsHashPropertyBag.h"
+#include "nsIProperty.h"
+#include "nsISimpleEnumerator.h"
+#include "nsIVariant.h"
+#include "nsServiceManagerUtils.h"
+#include "nsNetAddr.h"
+#include "nsNetCID.h"
+#include "nsSocketTransportService2.h"
+#include "nsThreadUtils.h"
+#include "nsXPCOMCID.h"
+#include "private/pprio.h"
+
+#include "nsASocketHandler.h"
+
+namespace mozilla {
+namespace net {
+
+static LazyLogModule gMDNSLog("MDNSResponderOperator");
+#undef LOG_I
+#define LOG_I(...) MOZ_LOG(mozilla::net::gMDNSLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
+#undef LOG_E
+#define LOG_E(...) MOZ_LOG(mozilla::net::gMDNSLog, mozilla::LogLevel::Error, (__VA_ARGS__))
+
+class MDNSResponderOperator::ServiceWatcher final
+  : public nsASocketHandler
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  // nsASocketHandler methods
+  virtual void OnSocketReady(PRFileDesc* fd, int16_t outFlags) override
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+    MOZ_ASSERT(fd == mFD);
+
+    if (outFlags & (PR_POLL_ERR | PR_POLL_HUP | PR_POLL_NVAL)) {
+      LOG_E("error polling on listening socket (%p)", fd);
+      mCondition = NS_ERROR_UNEXPECTED;
+    }
+
+    if (!(outFlags & PR_POLL_READ)) {
+      return;
+    }
+
+    DNSServiceProcessResult(mService);
+  }
+
+  virtual void OnSocketDetached(PRFileDesc *fd) override
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+    MOZ_ASSERT(mThread);
+    MOZ_ASSERT(fd == mFD);
+
+    if (!mFD) {
+      return;
+    }
+
+    // Bug 1175387: do not double close the handle here.
+    PR_ChangeFileDescNativeHandle(mFD, -1);
+    PR_Close(mFD);
+    mFD = nullptr;
+
+    mThread->Dispatch(NewRunnableMethod(this, &ServiceWatcher::Deallocate),
+                      NS_DISPATCH_NORMAL);
+  }
+
+  virtual void IsLocal(bool *aIsLocal) override { *aIsLocal = true; }
+
+  virtual void KeepWhenOffline(bool *aKeepWhenOffline) override
+  {
+    *aKeepWhenOffline = true;
+  }
+
+  virtual uint64_t ByteCountSent() override { return 0; }
+  virtual uint64_t ByteCountReceived() override { return 0; }
+
+  explicit ServiceWatcher(DNSServiceRef aService,
+                          MDNSResponderOperator* aOperator)
+    : mThread(nullptr)
+    , mSts(nullptr)
+    , mOperatorHolder(aOperator)
+    , mService(aService)
+    , mFD(nullptr)
+    , mAttached(false)
+  {
+    if (!gSocketTransportService)
+    {
+      nsCOMPtr<nsISocketTransportService> sts =
+        do_GetService(NS_SOCKETTRANSPORTSERVICE_CONTRACTID);
+    }
+  }
+
+  nsresult Init()
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() != gSocketThread);
+    mThread = NS_GetCurrentThread();
+
+    if (!mService) {
+      return NS_OK;
+    }
+
+    if (!gSocketTransportService) {
+      return NS_ERROR_FAILURE;
+    }
+    mSts = gSocketTransportService;
+
+    int osfd = DNSServiceRefSockFD(mService);
+    if (osfd == -1) {
+      return NS_ERROR_FAILURE;
+    }
+
+    mFD = PR_ImportFile(osfd);
+    return PostEvent(&ServiceWatcher::OnMsgAttach);
+  }
+
+  void Close()
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() != gSocketThread);
+
+    if (!gSocketTransportService) {
+      Deallocate();
+      return;
+    }
+
+    PostEvent(&ServiceWatcher::OnMsgClose);
+  }
+
+private:
+  ~ServiceWatcher() = default;
+
+  void Deallocate()
+  {
+    if (mService) {
+      DNSServiceRefDeallocate(mService);
+      mService = nullptr;
+    }
+    mOperatorHolder = nullptr;
+  }
+
+  nsresult PostEvent(void(ServiceWatcher::*func)(void))
+  {
+    return gSocketTransportService->Dispatch(NewRunnableMethod(this, func),
+                                             NS_DISPATCH_NORMAL);
+  }
+
+  void OnMsgClose()
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+    if (NS_FAILED(mCondition)) {
+      return;
+    }
+
+    // tear down socket. this signals the STS to detach our socket handler.
+    mCondition = NS_BINDING_ABORTED;
+
+    // if we are attached, then socket transport service will call our
+    // OnSocketDetached method automatically. Otherwise, we have to call it
+    // (and thus close the socket) manually.
+    if (!mAttached) {
+      OnSocketDetached(mFD);
+    }
+  }
+
+  void OnMsgAttach()
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+    if (NS_FAILED(mCondition)) {
+      return;
+    }
+
+    mCondition = TryAttach();
+
+    // if we hit an error while trying to attach then bail...
+    if (NS_FAILED(mCondition)) {
+      NS_ASSERTION(!mAttached, "should not be attached already");
+      OnSocketDetached(mFD);
+    }
+
+  }
+
+  nsresult TryAttach()
+  {
+    MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+    nsresult rv;
+
+    if (!gSocketTransportService) {
+      return NS_ERROR_FAILURE;
+    }
+
+    //
+    // find out if it is going to be ok to attach another socket to the STS.
+    // if not then we have to wait for the STS to tell us that it is ok.
+    // the notification is asynchronous, which means that when we could be
+    // in a race to call AttachSocket once notified.  for this reason, when
+    // we get notified, we just re-enter this function.  as a result, we are
+    // sure to ask again before calling AttachSocket.  in this way we deal
+    // with the race condition.  though it isn't the most elegant solution,
+    // it is far simpler than trying to build a system that would guarantee
+    // FIFO ordering (which wouldn't even be that valuable IMO).  see bug
+    // 194402 for more info.
+    //
+    if (!gSocketTransportService->CanAttachSocket()) {
+      nsCOMPtr<nsIRunnable> event =
+        NewRunnableMethod(this, &ServiceWatcher::OnMsgAttach);
+
+      nsresult rv = gSocketTransportService->NotifyWhenCanAttachSocket(event);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+    }
+
+    //
+    // ok, we can now attach our socket to the STS for polling
+    //
+    rv = gSocketTransportService->AttachSocket(mFD, this);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    mAttached = true;
+
+    //
+    // now, configure our poll flags for listening...
+    //
+    mPollFlags = (PR_POLL_READ | PR_POLL_EXCEPT);
+
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIThread> mThread;
+  RefPtr<nsSocketTransportService> mSts;
+  RefPtr<MDNSResponderOperator> mOperatorHolder;
+  DNSServiceRef mService;
+  PRFileDesc* mFD;
+  bool mAttached;
+};
+
+NS_IMPL_ISUPPORTS(MDNSResponderOperator::ServiceWatcher, nsISupports)
+
+MDNSResponderOperator::MDNSResponderOperator()
+  : mService(nullptr)
+  , mWatcher(nullptr)
+  , mThread(NS_GetCurrentThread())
+  , mIsCancelled(false)
+{
+}
+
+MDNSResponderOperator::~MDNSResponderOperator()
+{
+  Stop();
+}
+
+nsresult
+MDNSResponderOperator::Start()
+{
+  if (mIsCancelled) {
+    return NS_OK;
+  }
+
+  if (IsServing()) {
+    Stop();
+  }
+
+  return NS_OK;
+}
+
+nsresult
+MDNSResponderOperator::Stop()
+{
+  return ResetService(nullptr);
+}
+
+nsresult
+MDNSResponderOperator::ResetService(DNSServiceRef aService)
+{
+  nsresult rv;
+
+  if (aService != mService) {
+    if (mWatcher) {
+      mWatcher->Close();
+      mWatcher = nullptr;
+    }
+
+    if (aService) {
+      RefPtr<ServiceWatcher> watcher = new ServiceWatcher(aService, this);
+      if (NS_WARN_IF(NS_FAILED(rv = watcher->Init()))) {
+        return rv;
+      }
+      mWatcher = watcher;
+    }
+
+    mService = aService;
+  }
+  return NS_OK;
+}
+
+BrowseOperator::BrowseOperator(const nsACString& aServiceType,
+                               nsIDNSServiceDiscoveryListener* aListener)
+  : MDNSResponderOperator()
+  , mServiceType(aServiceType)
+  , mListener(aListener)
+{
+}
+
+nsresult
+BrowseOperator::Start()
+{
+  nsresult rv;
+  if (NS_WARN_IF(NS_FAILED(rv = MDNSResponderOperator::Start()))) {
+    return rv;
+  }
+
+  DNSServiceRef service = nullptr;
+  DNSServiceErrorType err = DNSServiceBrowse(&service,
+                                             0,
+                                             kDNSServiceInterfaceIndexAny,
+                                             mServiceType.get(),
+                                             nullptr,
+                                             &BrowseReplyRunnable::Reply,
+                                             this);
+  NS_WARNING_ASSERTION(kDNSServiceErr_NoError == err, "DNSServiceBrowse fail");
+
+  if (mListener) {
+    if (kDNSServiceErr_NoError == err) {
+      mListener->OnDiscoveryStarted(mServiceType);
+    } else {
+      mListener->OnStartDiscoveryFailed(mServiceType, err);
+    }
+  }
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != err)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return ResetService(service);
+}
+
+nsresult
+BrowseOperator::Stop()
+{
+  bool isServing = IsServing();
+  nsresult rv = MDNSResponderOperator::Stop();
+
+  if (isServing && mListener) {
+    if (NS_SUCCEEDED(rv)) {
+      mListener->OnDiscoveryStopped(mServiceType);
+    } else {
+      mListener->OnStopDiscoveryFailed(mServiceType,
+                                       static_cast<uint32_t>(rv));
+    }
+  }
+
+  return rv;
+}
+
+void
+BrowseOperator::Reply(DNSServiceRef aSdRef,
+                      DNSServiceFlags aFlags,
+                      uint32_t aInterfaceIndex,
+                      DNSServiceErrorType aErrorCode,
+                      const nsACString& aServiceName,
+                      const nsACString& aRegType,
+                      const nsACString& aReplyDomain)
+{
+  MOZ_ASSERT(GetThread() == NS_GetCurrentThread());
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != aErrorCode)) {
+    LOG_E("BrowseOperator::Reply (%d)", aErrorCode);
+    if (mListener) {
+      mListener->OnStartDiscoveryFailed(mServiceType, aErrorCode);
+    }
+    return;
+  }
+
+  if (!mListener) { return; }
+  nsCOMPtr<nsIDNSServiceInfo> info = new nsDNSServiceInfo();
+
+  if (NS_WARN_IF(!info)) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetServiceName(aServiceName)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetServiceType(aRegType)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetDomainName(aReplyDomain)))) { return; }
+
+  if (aFlags & kDNSServiceFlagsAdd) {
+    mListener->OnServiceFound(info);
+  } else {
+    mListener->OnServiceLost(info);
+  }
+}
+
+RegisterOperator::RegisterOperator(nsIDNSServiceInfo* aServiceInfo,
+                                   nsIDNSRegistrationListener* aListener)
+  : MDNSResponderOperator()
+  , mServiceInfo(aServiceInfo)
+  , mListener(aListener)
+{
+}
+
+nsresult
+RegisterOperator::Start()
+{
+  nsresult rv;
+
+  rv = MDNSResponderOperator::Start();
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  uint16_t port;
+  if (NS_WARN_IF(NS_FAILED(rv = mServiceInfo->GetPort(&port)))) {
+    return rv;
+  }
+  nsAutoCString type;
+  if (NS_WARN_IF(NS_FAILED(rv = mServiceInfo->GetServiceType(type)))) {
+    return rv;
+  }
+
+  TXTRecordRef txtRecord;
+  char buf[TXT_BUFFER_SIZE] = { 0 };
+  TXTRecordCreate(&txtRecord, TXT_BUFFER_SIZE, buf);
+
+  nsCOMPtr<nsIPropertyBag2> attributes;
+  if (NS_FAILED(rv = mServiceInfo->GetAttributes(getter_AddRefs(attributes)))) {
+    LOG_I("register: no attributes");
+  } else {
+    nsCOMPtr<nsISimpleEnumerator> enumerator;
+    if (NS_WARN_IF(NS_FAILED(rv =
+        attributes->GetEnumerator(getter_AddRefs(enumerator))))) {
+      return rv;
+    }
+
+    bool hasMoreElements;
+    while (NS_SUCCEEDED(enumerator->HasMoreElements(&hasMoreElements)) &&
+           hasMoreElements) {
+      nsCOMPtr<nsISupports> element;
+      MOZ_ALWAYS_SUCCEEDS(enumerator->GetNext(getter_AddRefs(element)));
+      nsCOMPtr<nsIProperty> property = do_QueryInterface(element);
+      MOZ_ASSERT(property);
+
+      nsAutoString name;
+      nsCOMPtr<nsIVariant> value;
+      MOZ_ALWAYS_SUCCEEDS(property->GetName(name));
+      MOZ_ALWAYS_SUCCEEDS(property->GetValue(getter_AddRefs(value)));
+
+      nsAutoCString str;
+      if (NS_WARN_IF(NS_FAILED(value->GetAsACString(str)))) {
+        continue;
+      }
+
+      TXTRecordSetValue(&txtRecord,
+                        /* it's safe because key name is ASCII only. */
+                        NS_LossyConvertUTF16toASCII(name).get(),
+                        str.Length(),
+                        str.get());
+    }
+  }
+
+  nsAutoCString host;
+  nsAutoCString name;
+  nsAutoCString domain;
+
+  DNSServiceRef service = nullptr;
+  DNSServiceErrorType err =
+    DNSServiceRegister(&service,
+                       0,
+                       0,
+                       NS_SUCCEEDED(mServiceInfo->GetServiceName(name)) ?
+                         name.get() : nullptr,
+                       type.get(),
+                       NS_SUCCEEDED(mServiceInfo->GetDomainName(domain)) ?
+                         domain.get() : nullptr,
+                       NS_SUCCEEDED(mServiceInfo->GetHost(host)) ?
+                         host.get() : nullptr,
+                       NativeEndian::swapToNetworkOrder(port),
+                       TXTRecordGetLength(&txtRecord),
+                       TXTRecordGetBytesPtr(&txtRecord),
+                       &RegisterReplyRunnable::Reply,
+                       this);
+  NS_WARNING_ASSERTION(kDNSServiceErr_NoError == err,
+                       "DNSServiceRegister fail");
+
+  TXTRecordDeallocate(&txtRecord);
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != err)) {
+    if (mListener) {
+      mListener->OnRegistrationFailed(mServiceInfo, err);
+    }
+    return NS_ERROR_FAILURE;
+  }
+
+  return ResetService(service);
+}
+
+nsresult
+RegisterOperator::Stop()
+{
+  bool isServing = IsServing();
+  nsresult rv = MDNSResponderOperator::Stop();
+
+  if (isServing && mListener) {
+    if (NS_SUCCEEDED(rv)) {
+      mListener->OnServiceUnregistered(mServiceInfo);
+    } else {
+      mListener->OnUnregistrationFailed(mServiceInfo,
+                                        static_cast<uint32_t>(rv));
+    }
+  }
+
+  return rv;
+}
+
+void
+RegisterOperator::Reply(DNSServiceRef aSdRef,
+                        DNSServiceFlags aFlags,
+                        DNSServiceErrorType aErrorCode,
+                        const nsACString& aName,
+                        const nsACString& aRegType,
+                        const nsACString& aDomain)
+{
+  MOZ_ASSERT(GetThread() == NS_GetCurrentThread());
+
+  if (kDNSServiceErr_NoError != aErrorCode) {
+    LOG_E("RegisterOperator::Reply (%d)", aErrorCode);
+  }
+
+  if (!mListener) { return; }
+  nsCOMPtr<nsIDNSServiceInfo> info = new nsDNSServiceInfo(mServiceInfo);
+  if (NS_WARN_IF(NS_FAILED(info->SetServiceName(aName)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetServiceType(aRegType)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetDomainName(aDomain)))) { return; }
+
+  if (kDNSServiceErr_NoError == aErrorCode) {
+    if (aFlags & kDNSServiceFlagsAdd) {
+      mListener->OnServiceRegistered(info);
+    } else {
+      // If a successfully-registered name later suffers a name conflict
+      // or similar problem and has to be deregistered, the callback will
+      // be invoked with the kDNSServiceFlagsAdd flag not set.
+      LOG_E("RegisterOperator::Reply: deregister");
+      if (NS_WARN_IF(NS_FAILED(Stop()))) {
+        return;
+      }
+    }
+  } else {
+    mListener->OnRegistrationFailed(info, aErrorCode);
+  }
+}
+
+ResolveOperator::ResolveOperator(nsIDNSServiceInfo* aServiceInfo,
+                                 nsIDNSServiceResolveListener* aListener)
+  : MDNSResponderOperator()
+  , mServiceInfo(aServiceInfo)
+  , mListener(aListener)
+{
+}
+
+nsresult
+ResolveOperator::Start()
+{
+  nsresult rv;
+  if (NS_WARN_IF(NS_FAILED(rv = MDNSResponderOperator::Start()))) {
+    return rv;
+  }
+
+  nsAutoCString name;
+  mServiceInfo->GetServiceName(name);
+  nsAutoCString type;
+  mServiceInfo->GetServiceType(type);
+  nsAutoCString domain;
+  mServiceInfo->GetDomainName(domain);
+
+  LOG_I("Resolve: (%s), (%s), (%s)", name.get(), type.get(), domain.get());
+
+  DNSServiceRef service = nullptr;
+  DNSServiceErrorType err =
+    DNSServiceResolve(&service,
+                      0,
+                      kDNSServiceInterfaceIndexAny,
+                      name.get(),
+                      type.get(),
+                      domain.get(),
+                      (DNSServiceResolveReply)&ResolveReplyRunnable::Reply,
+                      this);
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != err)) {
+    if (mListener) {
+      mListener->OnResolveFailed(mServiceInfo, err);
+    }
+    return NS_ERROR_FAILURE;
+  }
+
+  return ResetService(service);
+}
+
+void
+ResolveOperator::Reply(DNSServiceRef aSdRef,
+                       DNSServiceFlags aFlags,
+                       uint32_t aInterfaceIndex,
+                       DNSServiceErrorType aErrorCode,
+                       const nsACString& aFullName,
+                       const nsACString& aHostTarget,
+                       uint16_t aPort,
+                       uint16_t aTxtLen,
+                       const unsigned char* aTxtRecord)
+{
+  MOZ_ASSERT(GetThread() == NS_GetCurrentThread());
+
+  auto guard = MakeScopeExit([&] {
+    Unused << NS_WARN_IF(NS_FAILED(Stop()));
+  });
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != aErrorCode)) {
+    LOG_E("ResolveOperator::Reply (%d)", aErrorCode);
+    return;
+  }
+
+  // Resolve TXT record
+  int count = TXTRecordGetCount(aTxtLen, aTxtRecord);
+  LOG_I("resolve: txt count = %d, len = %d", count, aTxtLen);
+  nsCOMPtr<nsIWritablePropertyBag2> attributes = new nsHashPropertyBag();
+  if (NS_WARN_IF(!attributes)) {
+    return;
+  }
+  if (count) {
+    for (int i = 0; i < count; ++i) {
+      char key[TXT_BUFFER_SIZE] = { '\0' };
+      uint8_t vSize = 0;
+      const void* value = nullptr;
+      if (kDNSServiceErr_NoError !=
+          TXTRecordGetItemAtIndex(aTxtLen,
+                                  aTxtRecord,
+                                  i,
+                                  TXT_BUFFER_SIZE,
+                                  key,
+                                  &vSize,
+                                  &value)) {
+        break;
+      }
+
+      nsAutoCString str(reinterpret_cast<const char*>(value), vSize);
+      LOG_I("resolve TXT: (%d) %s=%s", vSize, key, str.get());
+
+      if (NS_WARN_IF(NS_FAILED(attributes->SetPropertyAsACString(
+          /* it's safe to convert because key name is ASCII only. */
+          NS_ConvertASCIItoUTF16(key),
+          str)))) {
+        break;
+      }
+    }
+  }
+
+  if (!mListener) { return; }
+  nsCOMPtr<nsIDNSServiceInfo> info = new nsDNSServiceInfo(mServiceInfo);
+  if (NS_WARN_IF(NS_FAILED(info->SetHost(aHostTarget)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetPort(aPort)))) { return; }
+  if (NS_WARN_IF(NS_FAILED(info->SetAttributes(attributes)))) { return; }
+
+  if (kDNSServiceErr_NoError == aErrorCode) {
+    GetAddrInfor(info);
+  }
+  else {
+    mListener->OnResolveFailed(info, aErrorCode);
+    Unused << NS_WARN_IF(NS_FAILED(Stop()));
+  }
+}
+
+void
+ResolveOperator::GetAddrInfor(nsIDNSServiceInfo* aServiceInfo)
+{
+  RefPtr<GetAddrInfoOperator> getAddreOp = new GetAddrInfoOperator(aServiceInfo,
+                                                                   mListener);
+  Unused << NS_WARN_IF(NS_FAILED(getAddreOp->Start()));
+}
+
+GetAddrInfoOperator::GetAddrInfoOperator(nsIDNSServiceInfo* aServiceInfo,
+                                         nsIDNSServiceResolveListener* aListener)
+  : MDNSResponderOperator()
+  , mServiceInfo(aServiceInfo)
+  , mListener(aListener)
+{
+}
+
+nsresult
+GetAddrInfoOperator::Start()
+{
+  nsresult rv;
+  if (NS_WARN_IF(NS_FAILED(rv = MDNSResponderOperator::Start()))) {
+    return rv;
+  }
+
+  nsAutoCString host;
+  mServiceInfo->GetHost(host);
+
+  LOG_I("GetAddrInfo: (%s)", host.get());
+
+  DNSServiceRef service = nullptr;
+  DNSServiceErrorType err =
+    DNSServiceGetAddrInfo(&service,
+                          kDNSServiceFlagsForceMulticast,
+                          kDNSServiceInterfaceIndexAny,
+                          kDNSServiceProtocol_IPv4 | kDNSServiceProtocol_IPv6,
+                          host.get(),
+                          (DNSServiceGetAddrInfoReply)&GetAddrInfoReplyRunnable::Reply,
+                          this);
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != err)) {
+    if (mListener) {
+      mListener->OnResolveFailed(mServiceInfo, err);
+    }
+    return NS_ERROR_FAILURE;
+  }
+
+  return ResetService(service);
+}
+
+void
+GetAddrInfoOperator::Reply(DNSServiceRef aSdRef,
+                           DNSServiceFlags aFlags,
+                           uint32_t aInterfaceIndex,
+                           DNSServiceErrorType aErrorCode,
+                           const nsACString& aHostName,
+                           const NetAddr& aAddress,
+                           uint32_t aTTL)
+{
+  MOZ_ASSERT(GetThread() == NS_GetCurrentThread());
+
+  auto guard = MakeScopeExit([&] {
+    Unused << NS_WARN_IF(NS_FAILED(Stop()));
+  });
+
+  if (NS_WARN_IF(kDNSServiceErr_NoError != aErrorCode)) {
+    LOG_E("GetAddrInfoOperator::Reply (%d)", aErrorCode);
+    return;
+  }
+
+  if (!mListener) { return; }
+
+  NetAddr addr = aAddress;
+  nsCOMPtr<nsINetAddr> address = new nsNetAddr(&addr);
+  nsCString addressStr;
+  if (NS_WARN_IF(NS_FAILED(address->GetAddress(addressStr)))) { return; }
+
+  nsCOMPtr<nsIDNSServiceInfo> info = new nsDNSServiceInfo(mServiceInfo);
+  if (NS_WARN_IF(NS_FAILED(info->SetAddress(addressStr)))) { return; }
+
+  /**
+   * |kDNSServiceFlagsMoreComing| means this callback will be one or more
+   * callback events later, so this instance should be kept alive until all
+   * follow-up events are processed.
+   */
+  if (aFlags & kDNSServiceFlagsMoreComing) {
+    guard.release();
+  }
+
+  if (kDNSServiceErr_NoError == aErrorCode) {
+    mListener->OnServiceResolved(info);
+  } else {
+    mListener->OnResolveFailed(info, aErrorCode);
+  }
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/dns/mdns/libmdns/MDNSResponderOperator.h b/netwerk/dns/mdns/libmdns/MDNSResponderOperator.h
new file mode 100644
index 000000000..a932baa7c
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/MDNSResponderOperator.h
@@ -0,0 +1,152 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_netwerk_dns_mdns_libmdns_MDNSResponderOperator_h
+#define mozilla_netwerk_dns_mdns_libmdns_MDNSResponderOperator_h
+
+#include "dns_sd.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsIDNSServiceDiscovery.h"
+#include "nsIThread.h"
+#include "nsString.h"
+
+namespace mozilla {
+namespace net {
+
+class MDNSResponderOperator
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MDNSResponderOperator)
+
+public:
+  MDNSResponderOperator();
+
+  virtual nsresult Start();
+  virtual nsresult Stop();
+  void Cancel() { mIsCancelled = true; }
+  nsIThread* GetThread() const { return mThread; }
+
+protected:
+  virtual ~MDNSResponderOperator();
+
+  bool IsServing() const { return mService; }
+  nsresult ResetService(DNSServiceRef aService);
+
+private:
+  class ServiceWatcher;
+
+  DNSServiceRef mService;
+  RefPtr<ServiceWatcher> mWatcher;
+  nsCOMPtr<nsIThread> mThread; // remember caller thread for callback
+  Atomic<bool> mIsCancelled;
+};
+
+class BrowseOperator final : public MDNSResponderOperator
+{
+public:
+  BrowseOperator(const nsACString& aServiceType,
+                 nsIDNSServiceDiscoveryListener* aListener);
+
+  nsresult Start() override;
+  nsresult Stop() override;
+
+  void Reply(DNSServiceRef aSdRef,
+             DNSServiceFlags aFlags,
+             uint32_t aInterfaceIndex,
+             DNSServiceErrorType aErrorCode,
+             const nsACString& aServiceName,
+             const nsACString& aRegType,
+             const nsACString& aReplyDomain);
+
+private:
+  ~BrowseOperator() = default;
+
+  nsCString mServiceType;
+  nsCOMPtr<nsIDNSServiceDiscoveryListener> mListener;
+};
+
+class RegisterOperator final : public MDNSResponderOperator
+{
+  enum { TXT_BUFFER_SIZE = 256 };
+
+public:
+  RegisterOperator(nsIDNSServiceInfo* aServiceInfo,
+                   nsIDNSRegistrationListener* aListener);
+
+  nsresult Start() override;
+  nsresult Stop() override;
+
+  void Reply(DNSServiceRef aSdRef,
+             DNSServiceFlags aFlags,
+             DNSServiceErrorType aErrorCode,
+             const nsACString& aName,
+             const nsACString& aRegType,
+             const nsACString& aDomain);
+
+private:
+  ~RegisterOperator() = default;
+
+  nsCOMPtr<nsIDNSServiceInfo> mServiceInfo;
+  nsCOMPtr<nsIDNSRegistrationListener> mListener;
+};
+
+class ResolveOperator final : public MDNSResponderOperator
+{
+  enum { TXT_BUFFER_SIZE = 256 };
+
+public:
+  ResolveOperator(nsIDNSServiceInfo* aServiceInfo,
+                  nsIDNSServiceResolveListener* aListener);
+
+  nsresult Start() override;
+
+  void Reply(DNSServiceRef aSdRef,
+             DNSServiceFlags aFlags,
+             uint32_t aInterfaceIndex,
+             DNSServiceErrorType aErrorCode,
+             const nsACString& aFullName,
+             const nsACString& aHostTarget,
+             uint16_t aPort,
+             uint16_t aTxtLen,
+             const unsigned char* aTxtRecord);
+
+private:
+  ~ResolveOperator() = default;
+  void GetAddrInfor(nsIDNSServiceInfo* aServiceInfo);
+
+  nsCOMPtr<nsIDNSServiceInfo> mServiceInfo;
+  nsCOMPtr<nsIDNSServiceResolveListener> mListener;
+};
+
+union NetAddr;
+
+class GetAddrInfoOperator final : public MDNSResponderOperator
+{
+public:
+  GetAddrInfoOperator(nsIDNSServiceInfo* aServiceInfo,
+                      nsIDNSServiceResolveListener* aListener);
+
+  nsresult Start() override;
+
+  void Reply(DNSServiceRef aSdRef,
+             DNSServiceFlags aFlags,
+             uint32_t aInterfaceIndex,
+             DNSServiceErrorType aErrorCode,
+             const nsACString& aHostName,
+             const NetAddr& aAddress,
+             uint32_t aTTL);
+
+private:
+  ~GetAddrInfoOperator() = default;
+
+  nsCOMPtr<nsIDNSServiceInfo> mServiceInfo;
+  nsCOMPtr<nsIDNSServiceResolveListener> mListener;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif // mozilla_netwerk_dns_mdns_libmdns_MDNSResponderOperator_h
diff --git a/netwerk/dns/mdns/libmdns/MDNSResponderReply.cpp b/netwerk/dns/mdns/libmdns/MDNSResponderReply.cpp
new file mode 100644
index 000000000..7aa5b3759
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/MDNSResponderReply.cpp
@@ -0,0 +1,302 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "MDNSResponderReply.h"
+#include "mozilla/EndianUtils.h"
+#include "private/pprio.h"
+
+namespace mozilla {
+namespace net {
+
+BrowseReplyRunnable::BrowseReplyRunnable(DNSServiceRef aSdRef,
+                                         DNSServiceFlags aFlags,
+                                         uint32_t aInterfaceIndex,
+                                         DNSServiceErrorType aErrorCode,
+                                         const nsACString& aServiceName,
+                                         const nsACString& aRegType,
+                                         const nsACString& aReplyDomain,
+                                         BrowseOperator* aContext)
+  : mSdRef(aSdRef)
+  , mFlags(aFlags)
+  , mInterfaceIndex(aInterfaceIndex)
+  , mErrorCode(aErrorCode)
+  , mServiceName(aServiceName)
+  , mRegType(aRegType)
+  , mReplyDomain(aReplyDomain)
+  , mContext(aContext)
+{
+}
+
+NS_IMETHODIMP
+BrowseReplyRunnable::Run()
+{
+  MOZ_ASSERT(mContext);
+  mContext->Reply(mSdRef,
+                  mFlags,
+                  mInterfaceIndex,
+                  mErrorCode,
+                  mServiceName,
+                  mRegType,
+                  mReplyDomain);
+  return NS_OK;
+}
+
+void
+BrowseReplyRunnable::Reply(DNSServiceRef aSdRef,
+                           DNSServiceFlags aFlags,
+                           uint32_t aInterfaceIndex,
+                           DNSServiceErrorType aErrorCode,
+                           const char* aServiceName,
+                           const char* aRegType,
+                           const char* aReplyDomain,
+                           void* aContext)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+  BrowseOperator* obj(reinterpret_cast<BrowseOperator*>(aContext));
+  if (!obj) {
+    return;
+  }
+
+  nsCOMPtr<nsIThread> thread(obj->GetThread());
+  if (!thread) {
+    return;
+  }
+
+  thread->Dispatch(new BrowseReplyRunnable(aSdRef,
+                                           aFlags,
+                                           aInterfaceIndex,
+                                           aErrorCode,
+                                           nsCString(aServiceName),
+                                           nsCString(aRegType),
+                                           nsCString(aReplyDomain),
+                                           obj),
+                   NS_DISPATCH_NORMAL);
+}
+
+RegisterReplyRunnable::RegisterReplyRunnable(DNSServiceRef aSdRef,
+                                             DNSServiceFlags aFlags,
+                                             DNSServiceErrorType aErrorCode,
+                                             const nsACString& aName,
+                                             const nsACString& aRegType,
+                                             const nsACString& domain,
+                                             RegisterOperator* aContext)
+  : mSdRef(aSdRef)
+  , mFlags(aFlags)
+  , mErrorCode(aErrorCode)
+  , mName(aName)
+  , mRegType(aRegType)
+  , mDomain(domain)
+  , mContext(aContext)
+{
+}
+
+NS_IMETHODIMP
+RegisterReplyRunnable::Run()
+{
+  MOZ_ASSERT(mContext);
+
+  mContext->Reply(mSdRef,
+                  mFlags,
+                  mErrorCode,
+                  mName,
+                  mRegType,
+                  mDomain);
+  return NS_OK;
+}
+
+void
+RegisterReplyRunnable::Reply(DNSServiceRef aSdRef,
+                             DNSServiceFlags aFlags,
+                             DNSServiceErrorType aErrorCode,
+                             const char* aName,
+                             const char* aRegType,
+                             const char* domain,
+                             void* aContext)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+  RegisterOperator* obj(reinterpret_cast<RegisterOperator*>(aContext));
+  if (!obj) {
+    return;
+  }
+
+  nsCOMPtr<nsIThread> thread(obj->GetThread());
+  if (!thread) {
+    return;
+  }
+
+  thread->Dispatch(new RegisterReplyRunnable(aSdRef,
+                                             aFlags,
+                                             aErrorCode,
+                                             nsCString(aName),
+                                             nsCString(aRegType),
+                                             nsCString(domain),
+                                             obj),
+                   NS_DISPATCH_NORMAL);
+}
+
+ResolveReplyRunnable::ResolveReplyRunnable(DNSServiceRef aSdRef,
+                                           DNSServiceFlags aFlags,
+                                           uint32_t aInterfaceIndex,
+                                           DNSServiceErrorType aErrorCode,
+                                           const nsACString& aFullName,
+                                           const nsACString& aHostTarget,
+                                           uint16_t aPort,
+                                           uint16_t aTxtLen,
+                                           const unsigned char* aTxtRecord,
+                                           ResolveOperator* aContext)
+  : mSdRef(aSdRef)
+  , mFlags(aFlags)
+  , mInterfaceIndex(aInterfaceIndex)
+  , mErrorCode(aErrorCode)
+  , mFullname(aFullName)
+  , mHosttarget(aHostTarget)
+  , mPort(aPort)
+  , mTxtLen(aTxtLen)
+  , mTxtRecord(new unsigned char[aTxtLen])
+  , mContext(aContext)
+{
+  if (mTxtRecord) {
+    memcpy(mTxtRecord.get(), aTxtRecord, aTxtLen);
+  }
+}
+
+ResolveReplyRunnable::~ResolveReplyRunnable()
+{
+}
+
+NS_IMETHODIMP
+ResolveReplyRunnable::Run()
+{
+  MOZ_ASSERT(mContext);
+  mContext->Reply(mSdRef,
+                  mFlags,
+                  mInterfaceIndex,
+                  mErrorCode,
+                  mFullname,
+                  mHosttarget,
+                  mPort,
+                  mTxtLen,
+                  mTxtRecord.get());
+  return NS_OK;
+}
+
+void
+ResolveReplyRunnable::Reply(DNSServiceRef aSdRef,
+                            DNSServiceFlags aFlags,
+                            uint32_t aInterfaceIndex,
+                            DNSServiceErrorType aErrorCode,
+                            const char* aFullName,
+                            const char* aHostTarget,
+                            uint16_t aPort,
+                            uint16_t aTxtLen,
+                            const unsigned char* aTxtRecord,
+                            void* aContext)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+  ResolveOperator* obj(reinterpret_cast<ResolveOperator*>(aContext));
+  if (!obj) {
+    return;
+  }
+
+  nsCOMPtr<nsIThread> thread(obj->GetThread());
+  if (!thread) {
+    return;
+  }
+
+  thread->Dispatch(new ResolveReplyRunnable(aSdRef,
+                                            aFlags,
+                                            aInterfaceIndex,
+                                            aErrorCode,
+                                            nsCString(aFullName),
+                                            nsCString(aHostTarget),
+                                            NativeEndian::swapFromNetworkOrder(aPort),
+                                            aTxtLen,
+                                            aTxtRecord,
+                                            obj),
+                   NS_DISPATCH_NORMAL);
+}
+
+GetAddrInfoReplyRunnable::GetAddrInfoReplyRunnable(DNSServiceRef aSdRef,
+                                                   DNSServiceFlags aFlags,
+                                                   uint32_t aInterfaceIndex,
+                                                   DNSServiceErrorType aErrorCode,
+                                                   const nsACString& aHostName,
+                                                   const mozilla::net::NetAddr& aAddress,
+                                                   uint32_t aTTL,
+                                                   GetAddrInfoOperator* aContext)
+  : mSdRef(aSdRef)
+  , mFlags(aFlags)
+  , mInterfaceIndex(aInterfaceIndex)
+  , mErrorCode(aErrorCode)
+  , mHostName(aHostName)
+  , mAddress(aAddress)
+  , mTTL(aTTL)
+  , mContext(aContext)
+{
+}
+
+GetAddrInfoReplyRunnable::~GetAddrInfoReplyRunnable()
+{
+}
+
+NS_IMETHODIMP
+GetAddrInfoReplyRunnable::Run()
+{
+  MOZ_ASSERT(mContext);
+  mContext->Reply(mSdRef,
+                  mFlags,
+                  mInterfaceIndex,
+                  mErrorCode,
+                  mHostName,
+                  mAddress,
+                  mTTL);
+  return NS_OK;
+}
+
+void
+GetAddrInfoReplyRunnable::Reply(DNSServiceRef aSdRef,
+                                DNSServiceFlags aFlags,
+                                uint32_t aInterfaceIndex,
+                                DNSServiceErrorType aErrorCode,
+                                const char* aHostName,
+                                const struct sockaddr* aAddress,
+                                uint32_t aTTL,
+                                void* aContext)
+{
+  MOZ_ASSERT(PR_GetCurrentThread() == gSocketThread);
+
+  GetAddrInfoOperator* obj(reinterpret_cast<GetAddrInfoOperator*>(aContext));
+  if (!obj) {
+    return;
+  }
+
+  nsCOMPtr<nsIThread> thread(obj->GetThread());
+  if (!thread) {
+    return;
+  }
+
+  NetAddr address;
+  address.raw.family = aAddress->sa_family;
+
+  static_assert(sizeof(address.raw.data) >= sizeof(aAddress->sa_data),
+                "size of sockaddr.sa_data is too big");
+  memcpy(&address.raw.data, aAddress->sa_data, sizeof(aAddress->sa_data));
+
+  thread->Dispatch(new GetAddrInfoReplyRunnable(aSdRef,
+                                                aFlags,
+                                                aInterfaceIndex,
+                                                aErrorCode,
+                                                nsCString(aHostName),
+                                                address,
+                                                aTTL,
+                                                obj),
+                   NS_DISPATCH_NORMAL);
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/dns/mdns/libmdns/MDNSResponderReply.h b/netwerk/dns/mdns/libmdns/MDNSResponderReply.h
new file mode 100644
index 000000000..794a585f8
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/MDNSResponderReply.h
@@ -0,0 +1,164 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_netwerk_dns_mdns_libmdns_MDNSResponderReply_h
+#define mozilla_netwerk_dns_mdns_libmdns_MDNSResponderReply_h
+
+#include "dns_sd.h"
+#include "MDNSResponderOperator.h"
+#include "mozilla/UniquePtr.h"
+#include "nsIThread.h"
+#include "mozilla/net/DNS.h"
+#include "mozilla/RefPtr.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace net {
+
+class BrowseReplyRunnable final : public Runnable
+{
+public:
+  BrowseReplyRunnable(DNSServiceRef aSdRef,
+                      DNSServiceFlags aFlags,
+                      uint32_t aInterfaceIndex,
+                      DNSServiceErrorType aErrorCode,
+                      const nsACString& aServiceName,
+                      const nsACString& aRegType,
+                      const nsACString& aReplyDomain,
+                      BrowseOperator* aContext);
+
+  NS_IMETHOD Run() override;
+
+  static void Reply(DNSServiceRef aSdRef,
+                    DNSServiceFlags aFlags,
+                    uint32_t aInterfaceIndex,
+                    DNSServiceErrorType aErrorCode,
+                    const char* aServiceName,
+                    const char* aRegType,
+                    const char* aReplyDomain,
+                    void* aContext);
+
+private:
+  DNSServiceRef mSdRef;
+  DNSServiceFlags mFlags;
+  uint32_t mInterfaceIndex;
+  DNSServiceErrorType mErrorCode;
+  nsCString mServiceName;
+  nsCString mRegType;
+  nsCString mReplyDomain;
+  RefPtr<BrowseOperator> mContext;
+};
+
+class RegisterReplyRunnable final : public Runnable
+{
+public:
+  RegisterReplyRunnable(DNSServiceRef aSdRef,
+                        DNSServiceFlags aFlags,
+                        DNSServiceErrorType aErrorCode,
+                        const nsACString& aName,
+                        const nsACString& aRegType,
+                        const nsACString& aDomain,
+                        RegisterOperator* aContext);
+
+  NS_IMETHOD Run() override;
+
+  static void Reply(DNSServiceRef aSdRef,
+                    DNSServiceFlags aFlags,
+                    DNSServiceErrorType aErrorCode,
+                    const char* aName,
+                    const char* aRegType,
+                    const char* aDomain,
+                    void* aContext);
+
+private:
+  DNSServiceRef mSdRef;
+  DNSServiceFlags mFlags;
+  DNSServiceErrorType mErrorCode;
+  nsCString mName;
+  nsCString mRegType;
+  nsCString mDomain;
+  RefPtr<RegisterOperator> mContext;
+};
+
+class ResolveReplyRunnable final : public Runnable
+{
+public:
+  ResolveReplyRunnable(DNSServiceRef aSdRef,
+                       DNSServiceFlags aFlags,
+                       uint32_t aInterfaceIndex,
+                       DNSServiceErrorType aErrorCode,
+                       const nsACString& aFullName,
+                       const nsACString& aHostTarget,
+                       uint16_t aPort,
+                       uint16_t aTxtLen,
+                       const unsigned char* aTxtRecord,
+                       ResolveOperator* aContext);
+  ~ResolveReplyRunnable();
+
+  NS_IMETHOD Run() override;
+
+  static void Reply(DNSServiceRef aSdRef,
+                    DNSServiceFlags aFlags,
+                    uint32_t aInterfaceIndex,
+                    DNSServiceErrorType aErrorCode,
+                    const char* aFullName,
+                    const char* aHostTarget,
+                    uint16_t aPort,
+                    uint16_t aTxtLen,
+                    const unsigned char* aTxtRecord,
+                    void* aContext);
+
+private:
+  DNSServiceRef mSdRef;
+  DNSServiceFlags mFlags;
+  uint32_t mInterfaceIndex;
+  DNSServiceErrorType mErrorCode;
+  nsCString mFullname;
+  nsCString mHosttarget;
+  uint16_t mPort;
+  uint16_t mTxtLen;
+  UniquePtr<unsigned char> mTxtRecord;
+  RefPtr<ResolveOperator> mContext;
+};
+
+class GetAddrInfoReplyRunnable final : public Runnable
+{
+public:
+  GetAddrInfoReplyRunnable(DNSServiceRef aSdRef,
+                           DNSServiceFlags aFlags,
+                           uint32_t aInterfaceIndex,
+                           DNSServiceErrorType aErrorCode,
+                           const nsACString& aHostName,
+                           const mozilla::net::NetAddr& aAddress,
+                           uint32_t aTTL,
+                           GetAddrInfoOperator* aContext);
+  ~GetAddrInfoReplyRunnable();
+
+  NS_IMETHOD Run() override;
+
+  static void Reply(DNSServiceRef aSdRef,
+                    DNSServiceFlags aFlags,
+                    uint32_t aInterfaceIndex,
+                    DNSServiceErrorType aErrorCode,
+                    const char* aHostName,
+                    const struct sockaddr* aAddress,
+                    uint32_t aTTL,
+                    void* aContext);
+
+private:
+  DNSServiceRef mSdRef;
+  DNSServiceFlags mFlags;
+  uint32_t mInterfaceIndex;
+  DNSServiceErrorType mErrorCode;
+  nsCString mHostName;
+  mozilla::net::NetAddr mAddress;
+  uint32_t mTTL;
+  RefPtr<GetAddrInfoOperator> mContext;
+};
+
+} // namespace net
+} // namespace mozilla
+
+ #endif // mozilla_netwerk_dns_mdns_libmdns_MDNSResponderReply_h
diff --git a/netwerk/dns/mdns/libmdns/MulticastDNSAndroid.jsm b/netwerk/dns/mdns/libmdns/MulticastDNSAndroid.jsm
new file mode 100644
index 000000000..771f9a794
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/MulticastDNSAndroid.jsm
@@ -0,0 +1,244 @@
+// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["MulticastDNS"];
+
+const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/Messaging.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+var log = Cu.import("resource://gre/modules/AndroidLog.jsm", {}).AndroidLog.d.bind(null, "MulticastDNS");
+
+const FAILURE_INTERNAL_ERROR = -65537;
+
+// Helper function for sending commands to Java.
+function send(type, data, callback) {
+  let msg = {
+    type: type
+  };
+
+  for (let i in data) {
+    try {
+      msg[i] = data[i];
+    } catch (e) {
+    }
+  }
+
+  Messaging.sendRequestForResult(msg)
+    .then(result => callback(result, null),
+          err => callback(null, typeof err === "number" ? err : FAILURE_INTERNAL_ERROR));
+}
+
+// Receives service found/lost event from NsdManager
+function ServiceManager() {
+}
+
+ServiceManager.prototype = {
+  listeners: {},
+  numListeners: 0,
+
+  registerEvent: function() {
+    log("registerEvent");
+    Messaging.addListener(this.onServiceFound.bind(this), "NsdManager:ServiceFound");
+    Messaging.addListener(this.onServiceLost.bind(this), "NsdManager:ServiceLost");
+  },
+
+  unregisterEvent: function() {
+    log("unregisterEvent");
+    Messaging.removeListener("NsdManager:ServiceFound");
+    Messaging.removeListener("NsdManager:ServiceLost");
+  },
+
+  addListener: function(aServiceType, aListener) {
+    log("addListener: " + aServiceType + ", " + aListener);
+
+    if (!this.listeners[aServiceType]) {
+      this.listeners[aServiceType] = [];
+    }
+    if (this.listeners[aServiceType].includes(aListener)) {
+      log("listener already exists");
+      return;
+    }
+
+    this.listeners[aServiceType].push(aListener);
+    ++this.numListeners;
+
+    if (this.numListeners === 1) {
+      this.registerEvent();
+    }
+
+    log("listener added: " + this);
+  },
+
+  removeListener: function(aServiceType, aListener) {
+    log("removeListener: " + aServiceType + ", " + aListener);
+
+    if (!this.listeners[aServiceType]) {
+      log("listener doesn't exist");
+      return;
+    }
+    let index = this.listeners[aServiceType].indexOf(aListener);
+    if (index < 0) {
+      log("listener doesn't exist");
+      return;
+    }
+
+    this.listeners[aServiceType].splice(index, 1);
+    --this.numListeners;
+
+    if (this.numListeners === 0) {
+      this.unregisterEvent();
+    }
+
+    log("listener removed" + this);
+  },
+
+  onServiceFound: function(aServiceInfo) {
+    let listeners = this.listeners[aServiceInfo.serviceType];
+    if (listeners) {
+      for (let listener of listeners) {
+        listener.onServiceFound(aServiceInfo);
+      }
+    } else {
+      log("no listener");
+    }
+    return {};
+  },
+
+  onServiceLost: function(aServiceInfo) {
+    let listeners = this.listeners[aServiceInfo.serviceType];
+    if (listeners) {
+      for (let listener of listeners) {
+        listener.onServiceLost(aServiceInfo);
+      }
+    } else {
+      log("no listener");
+    }
+    return {};
+  }
+};
+
+// make an object from nsIPropertyBag2
+function parsePropertyBag2(bag) {
+  if (!bag || !(bag instanceof Ci.nsIPropertyBag2)) {
+    throw new TypeError("Not a property bag");
+  }
+
+  let attributes = [];
+  let enumerator = bag.enumerator;
+  while (enumerator.hasMoreElements()) {
+    let name = enumerator.getNext().QueryInterface(Ci.nsIProperty).name;
+    let value = bag.getPropertyAsACString(name);
+    attributes.push({
+      "name": name,
+      "value": value
+    });
+  }
+
+  return attributes;
+}
+
+function MulticastDNS() {
+  this.serviceManager = new ServiceManager();
+}
+
+MulticastDNS.prototype = {
+  startDiscovery: function(aServiceType, aListener) {
+    this.serviceManager.addListener(aServiceType, aListener);
+
+    let serviceInfo = {
+      serviceType: aServiceType,
+      uniqueId: aListener.uuid
+    };
+
+    send("NsdManager:DiscoverServices", serviceInfo, (result, err) => {
+      if (err) {
+        log("onStartDiscoveryFailed: " + aServiceType + " (" + err + ")");
+        this.serviceManager.removeListener(aServiceType, aListener);
+        aListener.onStartDiscoveryFailed(aServiceType, err);
+      } else {
+        aListener.onDiscoveryStarted(result);
+      }
+    });
+  },
+
+  stopDiscovery: function(aServiceType, aListener) {
+    this.serviceManager.removeListener(aServiceType, aListener);
+
+    let serviceInfo = {
+      uniqueId: aListener.uuid
+    };
+
+    send("NsdManager:StopServiceDiscovery", serviceInfo, (result, err) => {
+      if (err) {
+        log("onStopDiscoveryFailed: " + aServiceType + " (" + err + ")");
+        aListener.onStopDiscoveryFailed(aServiceType, err);
+      } else {
+        aListener.onDiscoveryStopped(aServiceType);
+      }
+    });
+  },
+
+  registerService: function(aServiceInfo, aListener) {
+    let serviceInfo = {
+      port: aServiceInfo.port,
+      serviceType: aServiceInfo.serviceType,
+      uniqueId: aListener.uuid
+    };
+
+    try {
+      serviceInfo.host = aServiceInfo.host;
+    } catch(e) {
+      // host unspecified
+    }
+    try {
+      serviceInfo.serviceName = aServiceInfo.serviceName;
+    } catch(e) {
+      // serviceName unspecified
+    }
+    try {
+      serviceInfo.attributes = parsePropertyBag2(aServiceInfo.attributes);
+    } catch(e) {
+      // attributes unspecified
+    }
+
+    send("NsdManager:RegisterService", serviceInfo, (result, err) => {
+      if (err) {
+        log("onRegistrationFailed: (" + err + ")");
+        aListener.onRegistrationFailed(aServiceInfo, err);
+      } else {
+        aListener.onServiceRegistered(result);
+      }
+    });
+  },
+
+  unregisterService: function(aServiceInfo, aListener) {
+    let serviceInfo = {
+      uniqueId: aListener.uuid
+    };
+
+    send("NsdManager:UnregisterService", serviceInfo, (result, err) => {
+      if (err) {
+        log("onUnregistrationFailed: (" + err + ")");
+        aListener.onUnregistrationFailed(aServiceInfo, err);
+      } else {
+        aListener.onServiceUnregistered(aServiceInfo);
+      }
+    });
+  },
+
+  resolveService: function(aServiceInfo, aListener) {
+    send("NsdManager:ResolveService", aServiceInfo, (result, err) => {
+      if (err) {
+        log("onResolveFailed: (" + err + ")");
+        aListener.onResolveFailed(aServiceInfo, err);
+      } else {
+        aListener.onServiceResolved(result);
+      }
+    });
+  }
+};
diff --git a/netwerk/dns/mdns/libmdns/fallback/DNSPacket.jsm b/netwerk/dns/mdns/libmdns/fallback/DNSPacket.jsm
new file mode 100644
index 000000000..f0539fccb
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DNSPacket.jsm
@@ -0,0 +1,297 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DNSPacket'];
+
+const { utils: Cu } = Components;
+
+Cu.import('resource://gre/modules/Services.jsm');
+
+Cu.import('resource://gre/modules/DataReader.jsm');
+Cu.import('resource://gre/modules/DataWriter.jsm');
+Cu.import('resource://gre/modules/DNSRecord.jsm');
+Cu.import('resource://gre/modules/DNSResourceRecord.jsm');
+
+const DEBUG = true;
+
+function debug(msg) {
+  Services.console.logStringMessage('DNSPacket: ' + msg);
+}
+
+let DNS_PACKET_SECTION_TYPES = [
+  'QD', // Question
+  'AN', // Answer
+  'NS', // Authority
+  'AR'  // Additional
+];
+
+/**
+ * DNS Packet Structure
+ * *************************************************
+ *
+ * Header
+ * ======
+ *
+ * 00                   2-Bytes                   15
+ * -------------------------------------------------
+ * |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|
+ * -------------------------------------------------
+ * |<==================== ID =====================>|
+ * |QR|<== OP ===>|AA|TC|RD|RA|UN|AD|CD|<== RC ===>|
+ * |<================== QDCOUNT ==================>|
+ * |<================== ANCOUNT ==================>|
+ * |<================== NSCOUNT ==================>|
+ * |<================== ARCOUNT ==================>|
+ * -------------------------------------------------
+ *
+ * ID:        2-Bytes
+ * FLAGS:     2-Bytes
+ *  - QR:     1-Bit
+ *  - OP:     4-Bits
+ *  - AA:     1-Bit
+ *  - TC:     1-Bit
+ *  - RD:     1-Bit
+ *  - RA:     1-Bit
+ *  - UN:     1-Bit
+ *  - AD:     1-Bit
+ *  - CD:     1-Bit
+ *  - RC:     4-Bits
+ * QDCOUNT:   2-Bytes
+ * ANCOUNT:   2-Bytes
+ * NSCOUNT:   2-Bytes
+ * ARCOUNT:   2-Bytes
+ *
+ *
+ * Data
+ * ====
+ *
+ * 00                   2-Bytes                   15
+ * -------------------------------------------------
+ * |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|
+ * -------------------------------------------------
+ * |<???=============== QD[...] ===============???>|
+ * |<???=============== AN[...] ===============???>|
+ * |<???=============== NS[...] ===============???>|
+ * |<???=============== AR[...] ===============???>|
+ * -------------------------------------------------
+ *
+ * QD:        ??-Bytes
+ * AN:        ??-Bytes
+ * NS:        ??-Bytes
+ * AR:        ??-Bytes
+ *
+ *
+ * Question Record
+ * ===============
+ *
+ * 00                   2-Bytes                   15
+ * -------------------------------------------------
+ * |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15|
+ * -------------------------------------------------
+ * |<???================ NAME =================???>|
+ * |<=================== TYPE ====================>|
+ * |<=================== CLASS ===================>|
+ * -------------------------------------------------
+ *
+ * NAME:      ??-Bytes
+ * TYPE:      2-Bytes
+ * CLASS:     2-Bytes
+ *
+ *
+ * Resource Record
+ * ===============
+ *
+ * 00                   4-Bytes                   31
+ * -------------------------------------------------
+ * |00|02|04|06|08|10|12|14|16|18|20|22|24|26|28|30|
+ * -------------------------------------------------
+ * |<???================ NAME =================???>|
+ * |<======= TYPE ========>|<======= CLASS =======>|
+ * |<==================== TTL ====================>|
+ * |<====== DATALEN ======>|<???==== DATA =====???>|
+ * -------------------------------------------------
+ *
+ * NAME:      ??-Bytes
+ * TYPE:      2-Bytes
+ * CLASS:     2-Bytes
+ * DATALEN:   2-Bytes
+ * DATA:      ??-Bytes (Specified By DATALEN)
+ */
+class DNSPacket {
+  constructor() {
+    this._flags = _valueToFlags(0x0000);
+    this._records = {};
+
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      this._records[sectionType] = [];
+    });
+  }
+
+  static parse(data) {
+    let reader = new DataReader(data);
+    if (reader.getValue(2) !== 0x0000) {
+      throw new Error('Packet must start with 0x0000');
+    }
+
+    let packet = new DNSPacket();
+    packet._flags = _valueToFlags(reader.getValue(2));
+
+    let recordCounts = {};
+
+    // Parse the record counts.
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      recordCounts[sectionType] = reader.getValue(2);
+    });
+
+    // Parse the actual records.
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      let recordCount = recordCounts[sectionType];
+      for (let i = 0; i < recordCount; i++) {
+        if (sectionType === 'QD') {
+          packet.addRecord(sectionType,
+              DNSRecord.parseFromPacketReader(reader));
+        }
+
+        else {
+          packet.addRecord(sectionType,
+              DNSResourceRecord.parseFromPacketReader(reader));
+        }
+      }
+    });
+
+    if (!reader.eof) {
+      DEBUG && debug('Did not complete parsing packet data');
+    }
+
+    return packet;
+  }
+
+  getFlag(flag) {
+    return this._flags[flag];
+  }
+
+  setFlag(flag, value) {
+    this._flags[flag] = value;
+  }
+
+  addRecord(sectionType, record) {
+    this._records[sectionType].push(record);
+  }
+
+  getRecords(sectionTypes, recordType) {
+    let records = [];
+
+    sectionTypes.forEach((sectionType) => {
+      records = records.concat(this._records[sectionType]);
+    });
+
+    if (!recordType) {
+      return records;
+    }
+
+    return records.filter(r => r.recordType === recordType);
+  }
+
+  serialize() {
+    let writer = new DataWriter();
+
+    // Write leading 0x0000 (2 bytes)
+    writer.putValue(0x0000, 2);
+
+    // Write `flags` (2 bytes)
+    writer.putValue(_flagsToValue(this._flags), 2);
+
+    // Write lengths of record sections (2 bytes each)
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      writer.putValue(this._records[sectionType].length, 2);
+    });
+
+    // Write records
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      this._records[sectionType].forEach((record) => {
+        writer.putBytes(record.serialize());
+      });
+    });
+
+    return writer.data;
+  }
+
+  toJSON() {
+    return JSON.stringify(this.toJSONObject());
+  }
+
+  toJSONObject() {
+    let result = {flags: this._flags};
+    DNS_PACKET_SECTION_TYPES.forEach((sectionType) => {
+      result[sectionType] = [];
+
+      let records = this._records[sectionType];
+      records.forEach((record) => {
+        result[sectionType].push(record.toJSONObject());
+      });
+    });
+
+    return result;
+  }
+}
+
+/**
+ * @private
+ */
+function _valueToFlags(value) {
+  return {
+    QR: (value & 0x8000) >> 15,
+    OP: (value & 0x7800) >> 11,
+    AA: (value & 0x0400) >> 10,
+    TC: (value & 0x0200) >>  9,
+    RD: (value & 0x0100) >>  8,
+    RA: (value & 0x0080) >>  7,
+    UN: (value & 0x0040) >>  6,
+    AD: (value & 0x0020) >>  5,
+    CD: (value & 0x0010) >>  4,
+    RC: (value & 0x000f) >>  0
+  };
+}
+
+/**
+ * @private
+ */
+function _flagsToValue(flags) {
+  let value = 0x0000;
+
+  value += flags.QR & 0x01;
+
+  value <<= 4;
+  value += flags.OP & 0x0f;
+
+  value <<= 1;
+  value += flags.AA & 0x01;
+
+  value <<= 1;
+  value += flags.TC & 0x01;
+
+  value <<= 1;
+  value += flags.RD & 0x01;
+
+  value <<= 1;
+  value += flags.RA & 0x01;
+
+  value <<= 1;
+  value += flags.UN & 0x01;
+
+  value <<= 1;
+  value += flags.AD & 0x01;
+
+  value <<= 1;
+  value += flags.CD & 0x01;
+
+  value <<= 4;
+  value += flags.RC & 0x0f;
+
+  return value;
+}
diff --git a/netwerk/dns/mdns/libmdns/fallback/DNSRecord.jsm b/netwerk/dns/mdns/libmdns/fallback/DNSRecord.jsm
new file mode 100644
index 000000000..f5d48731f
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DNSRecord.jsm
@@ -0,0 +1,70 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DNSRecord'];
+
+const { utils: Cu } = Components;
+
+Cu.import('resource://gre/modules/DataWriter.jsm');
+Cu.import('resource://gre/modules/DNSTypes.jsm');
+
+class DNSRecord {
+  constructor(properties = {}) {
+    this.name       = properties.name       || '';
+    this.recordType = properties.recordType || DNS_RECORD_TYPES.ANY;
+    this.classCode  = properties.classCode  || DNS_CLASS_CODES.IN;
+    this.cacheFlush = properties.cacheFlush || false;
+  }
+
+  static parseFromPacketReader(reader) {
+    let name       = reader.getLabel();
+    let recordType = reader.getValue(2);
+    let classCode  = reader.getValue(2);
+    let cacheFlush = (classCode & 0x8000) ? true : false;
+    classCode &= 0xff;
+
+    return new this({
+      name: name,
+      recordType: recordType,
+      classCode: classCode,
+      cacheFlush: cacheFlush
+    });
+  }
+
+  serialize() {
+    let writer = new DataWriter();
+
+    // Write `name` (ends with trailing 0x00 byte)
+    writer.putLabel(this.name);
+
+    // Write `recordType` (2 bytes)
+    writer.putValue(this.recordType, 2);
+
+    // Write `classCode` (2 bytes)
+    let classCode = this.classCode;
+    if (this.cacheFlush) {
+      classCode |= 0x8000;
+    }
+    writer.putValue(classCode, 2);
+
+    return writer.data;
+  }
+
+  toJSON() {
+    return JSON.stringify(this.toJSONObject());
+  }
+
+  toJSONObject() {
+    return {
+      name: this.name,
+      recordType: this.recordType,
+      classCode: this.classCode,
+      cacheFlush: this.cacheFlush
+    };
+  }
+}
diff --git a/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm b/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm
new file mode 100644
index 000000000..ba0072a50
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DNSResourceRecord.jsm
@@ -0,0 +1,221 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DNSResourceRecord'];
+
+const { utils: Cu } = Components;
+
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://gre/modules/DataReader.jsm');
+Cu.import('resource://gre/modules/DataWriter.jsm');
+Cu.import('resource://gre/modules/DNSRecord.jsm');
+Cu.import('resource://gre/modules/DNSTypes.jsm');
+
+function debug(msg) {
+  Services.console.logStringMessage('MulticastDNS: ' + msg);
+}
+
+const DNS_RESOURCE_RECORD_DEFAULT_TTL = 120; // 120 seconds
+
+class DNSResourceRecord extends DNSRecord {
+  constructor(properties = {}) {
+    super(properties);
+
+    this.ttl  = properties.ttl  || DNS_RESOURCE_RECORD_DEFAULT_TTL;
+    this.data = properties.data || {};
+  }
+
+  static parseFromPacketReader(reader) {
+    let record = super.parseFromPacketReader(reader);
+
+    let ttl        = reader.getValue(4);
+    let recordData = reader.getBytes(reader.getValue(2));
+    let packetData = reader.data;
+
+    let data;
+
+    switch (record.recordType) {
+      case DNS_RECORD_TYPES.A:
+        data = _parseA(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.PTR:
+        data = _parsePTR(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.TXT:
+        data = _parseTXT(recordData, packetData);
+        break;
+      case DNS_RECORD_TYPES.SRV:
+        data = _parseSRV(recordData, packetData);
+        break;
+      default:
+        data = null;
+        break;
+    }
+
+    record.ttl  = ttl;
+    record.data = data;
+
+    return record;
+  }
+
+  serialize() {
+    let writer = new DataWriter(super.serialize());
+
+    // Write `ttl` (4 bytes)
+    writer.putValue(this.ttl, 4);
+
+    let data;
+
+    switch (this.recordType) {
+      case DNS_RECORD_TYPES.A:
+        data = _serializeA(this.data);
+        break;
+      case DNS_RECORD_TYPES.PTR:
+        data = _serializePTR(this.data);
+        break;
+      case DNS_RECORD_TYPES.TXT:
+        data = _serializeTXT(this.data);
+        break;
+      case DNS_RECORD_TYPES.SRV:
+        data = _serializeSRV(this.data);
+        break;
+      default:
+        data = new Uint8Array();
+        break;
+    }
+
+    // Write `data` length.
+    writer.putValue(data.length, 2);
+
+    // Write `data` (ends with trailing 0x00 byte)
+    writer.putBytes(data);
+
+    return writer.data;
+  }
+
+  toJSON() {
+    return JSON.stringify(this.toJSONObject());
+  }
+
+  toJSONObject() {
+    let result = super.toJSONObject();
+    result.ttl = this.ttl;
+    result.data = this.data;
+    return result;
+  }
+}
+
+/**
+ * @private
+ */
+function _parseA(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let parts = [];
+  for (let i = 0; i < 4; i++) {
+    parts.push(reader.getValue(1));
+  }
+
+  return parts.join('.');
+}
+
+/**
+ * @private
+ */
+function _parsePTR(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  return reader.getLabel(packetData);
+}
+
+/**
+ * @private
+ */
+function _parseTXT(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let result = {};
+
+  let label = reader.getLabel(packetData);
+  if (label.length > 0) {
+    let parts = label.split('.');
+    parts.forEach((part) => {
+      let [name] = part.split('=', 1);
+      let value = part.substr(name.length + 1);
+      result[name] = value;
+    });
+  }
+
+  return result;
+}
+
+/**
+ * @private
+ */
+function _parseSRV(recordData, packetData) {
+  let reader = new DataReader(recordData);
+
+  let priority = reader.getValue(2);
+  let weight   = reader.getValue(2);
+  let port     = reader.getValue(2);
+  let target   = reader.getLabel(packetData);
+
+  return { priority, weight, port, target };
+}
+
+/**
+ * @private
+ */
+function _serializeA(data) {
+  let writer = new DataWriter();
+
+  let parts = data.split('.');
+  for (let i = 0; i < 4; i++) {
+    writer.putValue(parseInt(parts[i], 10) || 0);
+  }
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializePTR(data) {
+  let writer = new DataWriter();
+
+  writer.putLabel(data);
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializeTXT(data) {
+  let writer = new DataWriter();
+
+  for (let name in data) {
+    writer.putLengthString(name + '=' + data[name]);
+  }
+
+  return writer.data;
+}
+
+/**
+ * @private
+ */
+function _serializeSRV(data) {
+  let writer = new DataWriter();
+
+  writer.putValue(data.priority || 0, 2);
+  writer.putValue(data.weight   || 0, 2);
+  writer.putValue(data.port     || 0, 2);
+  writer.putLabel(data.target);
+
+  return writer.data;
+}
diff --git a/netwerk/dns/mdns/libmdns/fallback/DNSTypes.jsm b/netwerk/dns/mdns/libmdns/fallback/DNSTypes.jsm
new file mode 100644
index 000000000..8c5470639
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DNSTypes.jsm
@@ -0,0 +1,100 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = [
+  'DNS_QUERY_RESPONSE_CODES',
+  'DNS_AUTHORITATIVE_ANSWER_CODES',
+  'DNS_CLASS_CODES',
+  'DNS_RECORD_TYPES'
+];
+
+let DNS_QUERY_RESPONSE_CODES = {
+  QUERY           : 0,      // RFC 1035 - Query
+  RESPONSE        : 1       // RFC 1035 - Reponse
+};
+
+let DNS_AUTHORITATIVE_ANSWER_CODES = {
+  NO              : 0,      // RFC 1035 - Not Authoritative
+  YES             : 1       // RFC 1035 - Is Authoritative
+};
+
+let DNS_CLASS_CODES = {
+  IN              : 0x01,   // RFC 1035 - Internet
+  CS              : 0x02,   // RFC 1035 - CSNET
+  CH              : 0x03,   // RFC 1035 - CHAOS
+  HS              : 0x04,   // RFC 1035 - Hesiod
+  NONE            : 0xfe,   // RFC 2136 - None
+  ANY             : 0xff,   // RFC 1035 - Any
+};
+
+let DNS_RECORD_TYPES = {
+  SIGZERO         : 0,      // RFC 2931
+  A               : 1,      // RFC 1035
+  NS              : 2,      // RFC 1035
+  MD              : 3,      // RFC 1035
+  MF              : 4,      // RFC 1035
+  CNAME           : 5,      // RFC 1035
+  SOA             : 6,      // RFC 1035
+  MB              : 7,      // RFC 1035
+  MG              : 8,      // RFC 1035
+  MR              : 9,      // RFC 1035
+  NULL            : 10,     // RFC 1035
+  WKS             : 11,     // RFC 1035
+  PTR             : 12,     // RFC 1035
+  HINFO           : 13,     // RFC 1035
+  MINFO           : 14,     // RFC 1035
+  MX              : 15,     // RFC 1035
+  TXT             : 16,     // RFC 1035
+  RP              : 17,     // RFC 1183
+  AFSDB           : 18,     // RFC 1183
+  X25             : 19,     // RFC 1183
+  ISDN            : 20,     // RFC 1183
+  RT              : 21,     // RFC 1183
+  NSAP            : 22,     // RFC 1706
+  NSAP_PTR        : 23,     // RFC 1348
+  SIG             : 24,     // RFC 2535
+  KEY             : 25,     // RFC 2535
+  PX              : 26,     // RFC 2163
+  GPOS            : 27,     // RFC 1712
+  AAAA            : 28,     // RFC 1886
+  LOC             : 29,     // RFC 1876
+  NXT             : 30,     // RFC 2535
+  EID             : 31,     // RFC ????
+  NIMLOC          : 32,     // RFC ????
+  SRV             : 33,     // RFC 2052
+  ATMA            : 34,     // RFC ????
+  NAPTR           : 35,     // RFC 2168
+  KX              : 36,     // RFC 2230
+  CERT            : 37,     // RFC 2538
+  DNAME           : 39,     // RFC 2672
+  OPT             : 41,     // RFC 2671
+  APL             : 42,     // RFC 3123
+  DS              : 43,     // RFC 4034
+  SSHFP           : 44,     // RFC 4255
+  IPSECKEY        : 45,     // RFC 4025
+  RRSIG           : 46,     // RFC 4034
+  NSEC            : 47,     // RFC 4034
+  DNSKEY          : 48,     // RFC 4034
+  DHCID           : 49,     // RFC 4701
+  NSEC3           : 50,     // RFC ????
+  NSEC3PARAM      : 51,     // RFC ????
+  HIP             : 55,     // RFC 5205
+  SPF             : 99,     // RFC 4408
+  UINFO           : 100,    // RFC ????
+  UID             : 101,    // RFC ????
+  GID             : 102,    // RFC ????
+  UNSPEC          : 103,    // RFC ????
+  TKEY            : 249,    // RFC 2930
+  TSIG            : 250,    // RFC 2931
+  IXFR            : 251,    // RFC 1995
+  AXFR            : 252,    // RFC 1035
+  MAILB           : 253,    // RFC 1035
+  MAILA           : 254,    // RFC 1035
+  ANY             : 255,    // RFC 1035
+  DLV             : 32769   // RFC 4431
+};
diff --git a/netwerk/dns/mdns/libmdns/fallback/DataReader.jsm b/netwerk/dns/mdns/libmdns/fallback/DataReader.jsm
new file mode 100644
index 000000000..a20c1dc32
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DataReader.jsm
@@ -0,0 +1,133 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DataReader'];
+
+class DataReader {
+  // `data` is `Uint8Array`
+  constructor(data, startByte = 0) {
+    this._data = data;
+    this._cursor = startByte;
+  }
+
+  get buffer() {
+    return this._data.buffer;
+  }
+
+  get data() {
+    return this._data;
+  }
+
+  get eof() {
+    return this._cursor >= this._data.length;
+  }
+
+  getBytes(length = 1) {
+    if (!length) {
+      return new Uint8Array();
+    }
+
+    let end = this._cursor + length;
+    if (end > this._data.length) {
+      return new Uint8Array();
+    }
+
+    let uint8Array = new Uint8Array(this.buffer.slice(this._cursor, end));
+    this._cursor += length;
+
+    return uint8Array;
+  }
+
+  getString(length) {
+    let uint8Array = this.getBytes(length);
+    return _uint8ArrayToString(uint8Array);
+  }
+
+  getValue(length) {
+    let uint8Array = this.getBytes(length);
+    return _uint8ArrayToValue(uint8Array);
+  }
+
+  getLabel(decompressData) {
+    let parts = [];
+    let partLength;
+
+    while ((partLength = this.getValue(1))) {
+      // If a length has been specified instead of a pointer,
+      // read the string of the specified length.
+      if (partLength !== 0xc0) {
+        parts.push(this.getString(partLength));
+        continue;
+      }
+
+      // TODO: Handle case where we have a pointer to the label
+      parts.push(String.fromCharCode(0xc0) + this.getString(1));
+      break;
+    }
+
+    let label = parts.join('.');
+
+    return _decompressLabel(label, decompressData || this._data);
+  }
+}
+
+/**
+ * @private
+ */
+function _uint8ArrayToValue(uint8Array) {
+  let length = uint8Array.length;
+  if (length === 0) {
+    return null;
+  }
+
+  let value = 0;
+  for (let i = 0; i < length; i++) {
+    value = value << 8;
+    value += uint8Array[i];
+  }
+
+  return value;
+}
+
+/**
+ * @private
+ */
+function _uint8ArrayToString(uint8Array) {
+  let length = uint8Array.length;
+  if (length === 0) {
+    return '';
+  }
+
+  let results = [];
+  for (let i = 0; i < length; i += 1024) {
+    results.push(String.fromCharCode.apply(null, uint8Array.subarray(i, i + 1024)));
+  }
+
+  return results.join('');
+}
+
+/**
+ * @private
+ */
+function _decompressLabel(label, decompressData) {
+  let result = '';
+
+  for (let i = 0, length = label.length; i < length; i++) {
+    if (label.charCodeAt(i) !== 0xc0) {
+      result += label.charAt(i);
+      continue;
+    }
+
+    i++;
+
+    let reader = new DataReader(decompressData, label.charCodeAt(i));
+    result += _decompressLabel(reader.getLabel(), decompressData);
+  }
+
+  return result;
+}
diff --git a/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm b/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm
new file mode 100644
index 000000000..af20d65f5
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm
@@ -0,0 +1,98 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DataWriter'];
+
+class DataWriter {
+  constructor(data, maxBytes = 512) {
+    if (typeof data === 'number') {
+      maxBytes = data;
+      data = undefined;
+    }
+
+    this._buffer = new ArrayBuffer(maxBytes);
+    this._data = new Uint8Array(this._buffer);
+    this._cursor = 0;
+
+    if (data) {
+      this.putBytes(data);
+    }
+  }
+
+  get buffer() {
+    return this._buffer.slice(0, this._cursor);
+  }
+
+  get data() {
+    return new Uint8Array(this.buffer);
+  }
+
+  // `data` is `Uint8Array`
+  putBytes(data) {
+    if (this._cursor + data.length > this._data.length) {
+      throw new Error('DataWriter buffer is exceeded');
+    }
+
+    for (let i = 0, length = data.length; i < length; i++) {
+      this._data[this._cursor] = data[i];
+      this._cursor++;
+    }
+  }
+
+  putByte(byte) {
+    if (this._cursor + 1 > this._data.length) {
+      throw new Error('DataWriter buffer is exceeded');
+    }
+
+    this._data[this._cursor] = byte
+    this._cursor++;
+  }
+
+  putValue(value, length) {
+    length = length || 1;
+    if (length == 1) {
+      this.putByte(value);
+    } else {
+      this.putBytes(_valueToUint8Array(value, length));
+    }
+  }
+
+  putLabel(label) {
+    // Eliminate any trailing '.'s in the label (valid in text representation).
+    label = label.replace(/\.$/, '');
+    let parts = label.split('.');
+    parts.forEach((part) => {
+      this.putLengthString(part);
+    });
+    this.putValue(0);
+  }
+
+  putLengthString(string) {
+    if (string.length > 0xff) {
+        throw new Error("String too long.");
+    }
+    this.putValue(string.length);
+    for (let i = 0; i < string.length; i++) {
+      this.putValue(string.charCodeAt(i));
+    }
+  }
+}
+
+/**
+ * @private
+ */
+function _valueToUint8Array(value, length) {
+  let arrayBuffer = new ArrayBuffer(length);
+  let uint8Array = new Uint8Array(arrayBuffer);
+  for (let i = length - 1; i >= 0; i--) {
+    uint8Array[i] = value & 0xff;
+    value = value >> 8;
+  }
+
+  return uint8Array;
+}
diff --git a/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm b/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm
new file mode 100644
index 000000000..f43dfd5f8
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/fallback/MulticastDNS.jsm
@@ -0,0 +1,875 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['MulticastDNS'];
+
+const { classes: Cc, interfaces: Ci, utils: Cu, results: Cr } = Components;
+
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import('resource://gre/modules/Timer.jsm');
+Cu.import('resource://gre/modules/XPCOMUtils.jsm');
+
+Cu.import('resource://gre/modules/DNSPacket.jsm');
+Cu.import('resource://gre/modules/DNSRecord.jsm');
+Cu.import('resource://gre/modules/DNSResourceRecord.jsm');
+Cu.import('resource://gre/modules/DNSTypes.jsm');
+
+const NS_NETWORK_LINK_TOPIC = 'network:link-status-changed';
+
+let observerService     = Cc["@mozilla.org/observer-service;1"]
+                            .getService(Components.interfaces.nsIObserverService);
+let networkInfoService  = Cc['@mozilla.org/network-info-service;1']
+                            .createInstance(Ci.nsINetworkInfoService);
+
+const DEBUG = true;
+
+const MDNS_MULTICAST_GROUP = '224.0.0.251';
+const MDNS_PORT            = 5353;
+const DEFAULT_TTL          = 120;
+
+function debug(msg) {
+  dump('MulticastDNS: ' + msg + '\n');
+}
+
+function ServiceKey(svc) {
+  return "" + svc.serviceType.length + "/" + svc.serviceType + "|" +
+              svc.serviceName.length + "/" + svc.serviceName + "|" +
+              svc.port;
+}
+
+function TryGet(obj, name) {
+  try {
+    return obj[name];
+  } catch (err) {
+    return undefined;
+  }
+}
+
+function IsIpv4Address(addr) {
+  let parts = addr.split('.');
+  if (parts.length != 4) {
+    return false;
+  }
+  for (let part of parts) {
+    let partInt = Number.parseInt(part, 10);
+    if (partInt.toString() != part) {
+      return false;
+    }
+    if (partInt < 0 || partInt >= 256) {
+      return false;
+    }
+  }
+  return true;
+}
+
+class PublishedService {
+  constructor(attrs) {
+    this.serviceType = attrs.serviceType.replace(/\.$/, '');
+    this.serviceName = attrs.serviceName;
+    this.domainName = TryGet(attrs, 'domainName') || "local";
+    this.address = TryGet(attrs, 'address') || "0.0.0.0";
+    this.port = attrs.port;
+    this.serviceAttrs = _propertyBagToObject(TryGet(attrs, 'attributes') || {});
+    this.host = TryGet(attrs, 'host');
+    this.key = this.generateKey();
+    this.lastAdvertised = undefined;
+    this.advertiseTimer = undefined;
+  }
+
+  equals(svc) {
+    return (this.port == svc.port) &&
+           (this.serviceName == svc.serviceName) &&
+           (this.serviceType == svc.serviceType);
+  }
+
+  generateKey() {
+    return ServiceKey(this);
+  }
+
+  ptrMatch(name) {
+    return name == (this.serviceType + "." + this.domainName);
+  }
+
+  clearAdvertiseTimer() {
+    if (!this.advertiseTimer) {
+      return;
+    }
+    clearTimeout(this.advertiseTimer);
+    this.advertiseTimer = undefined;
+  }
+}
+
+class MulticastDNS {
+  constructor() {
+    this._listeners       = new Map();
+    this._sockets         = new Map();
+    this._services        = new Map();
+    this._discovered      = new Map();
+    this._querySocket     = undefined;
+    this._broadcastReceiverSocket = undefined;
+    this._broadcastTimer  = undefined;
+
+    this._networkLinkObserver = {
+      observe: (subject, topic, data) => {
+        DEBUG && debug(NS_NETWORK_LINK_TOPIC + '(' + data + '); Clearing list of previously discovered services');
+        this._discovered.clear();
+      }
+    };
+  }
+
+  _attachNetworkLinkObserver() {
+    if (this._networkLinkObserverTimeout) {
+      clearTimeout(this._networkLinkObserverTimeout);
+    }
+
+    if (!this._isNetworkLinkObserverAttached) {
+      DEBUG && debug('Attaching observer ' + NS_NETWORK_LINK_TOPIC);
+      observerService.addObserver(this._networkLinkObserver, NS_NETWORK_LINK_TOPIC, false);
+      this._isNetworkLinkObserverAttached = true;
+    }
+  }
+
+  _detachNetworkLinkObserver() {
+    if (this._isNetworkLinkObserverAttached) {
+      if (this._networkLinkObserverTimeout) {
+        clearTimeout(this._networkLinkObserverTimeout);
+      }
+
+      this._networkLinkObserverTimeout = setTimeout(() => {
+        DEBUG && debug('Detaching observer ' + NS_NETWORK_LINK_TOPIC);
+        observerService.removeObserver(this._networkLinkObserver, NS_NETWORK_LINK_TOPIC);
+        this._isNetworkLinkObserverAttached = false;
+        this._networkLinkObserverTimeout = null;
+      }, 5000);
+    }
+  }
+
+  startDiscovery(aServiceType, aListener) {
+    DEBUG && debug('startDiscovery("' + aServiceType + '")');
+    let { serviceType } = _parseServiceDomainName(aServiceType);
+
+    this._attachNetworkLinkObserver();
+    this._addServiceListener(serviceType, aListener);
+
+    try {
+      this._query(serviceType + '.local');
+      aListener.onDiscoveryStarted(serviceType);
+    } catch (e) {
+      DEBUG && debug('startDiscovery("' + serviceType + '") FAILED: ' + e);
+      this._removeServiceListener(serviceType, aListener);
+      aListener.onStartDiscoveryFailed(serviceType, Cr.NS_ERROR_FAILURE);
+    }
+  }
+
+  stopDiscovery(aServiceType, aListener) {
+    DEBUG && debug('stopDiscovery("' + aServiceType + '")');
+    let { serviceType } = _parseServiceDomainName(aServiceType);
+
+    this._detachNetworkLinkObserver();
+    this._removeServiceListener(serviceType, aListener);
+
+    aListener.onDiscoveryStopped(serviceType);
+
+    this._checkCloseSockets();
+  }
+
+  resolveService(aServiceInfo, aListener) {
+    DEBUG && debug('resolveService(): ' + aServiceInfo.serviceName);
+
+    // Address info is already resolved during discovery
+    setTimeout(() => aListener.onServiceResolved(aServiceInfo));
+  }
+
+  registerService(aServiceInfo, aListener) {
+    DEBUG && debug('registerService(): ' + aServiceInfo.serviceName);
+
+    // Initialize the broadcast receiver socket in case it
+    // hasn't already been started so we can listen for
+    // multicast queries/announcements on all interfaces.
+    this._getBroadcastReceiverSocket();
+
+    for (let name of ['port', 'serviceName', 'serviceType']) {
+      if (!TryGet(aServiceInfo, name)) {
+        aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE);
+        throw new Error('Invalid nsIDNSServiceInfo; Missing "' + name + '"');
+      }
+    }
+
+    let publishedService;
+    try {
+      publishedService = new PublishedService(aServiceInfo);
+    } catch (e) {
+      DEBUG && debug("Error constructing PublishedService: " + e + " - " + e.stack);
+      setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+      return;
+    }
+
+    // Ensure such a service does not already exist.
+    if (this._services.get(publishedService.key)) {
+      setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+      return;
+    }
+
+    // Make sure that the service addr is '0.0.0.0', or there is at least one
+    // socket open on the address the service is open on.
+    this._getSockets().then((sockets) => {
+      if (publishedService.address != '0.0.0.0' && !sockets.get(publishedService.address)) {
+        setTimeout(() => aListener.onRegistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+        return;
+      }
+
+      this._services.set(publishedService.key, publishedService);
+
+      // Service registered.. call onServiceRegistered on next tick.
+      setTimeout(() => aListener.onServiceRegistered(aServiceInfo));
+
+      // Set a timeout to start advertising the service too.
+      publishedService.advertiseTimer = setTimeout(() => {
+        this._advertiseService(publishedService.key, /* firstAdv = */ true);
+      });
+    });
+  }
+
+  unregisterService(aServiceInfo, aListener) {
+    DEBUG && debug('unregisterService(): ' + aServiceInfo.serviceName);
+
+    let serviceKey;
+    try {
+      serviceKey = ServiceKey(aServiceInfo);
+    } catch (e) {
+      setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+      return;
+    }
+
+    let publishedService = this._services.get(serviceKey);
+    if (!publishedService) {
+      setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+      return;
+    }
+
+    // Clear any advertise timeout for this published service.
+    publishedService.clearAdvertiseTimer();
+
+    // Delete the service from the service map.
+    if (!this._services.delete(serviceKey)) {
+      setTimeout(() => aListener.onUnregistrationFailed(aServiceInfo, Cr.NS_ERROR_FAILURE));
+      return;
+    }
+
+    // Check the broadcast timer again to rejig when it should run next.
+    this._checkStartBroadcastTimer();
+
+    // Check to see if sockets should be closed, and if so close them.
+    this._checkCloseSockets();
+
+    aListener.onServiceUnregistered(aServiceInfo);
+  }
+
+  _respondToQuery(serviceKey, message) {
+    let address = message.fromAddr.address;
+    let port = message.fromAddr.port;
+    DEBUG && debug('_respondToQuery(): key=' + serviceKey + ', fromAddr='
+                        + address + ":" + port);
+
+    let publishedService = this._services.get(serviceKey);
+    if (!publishedService) {
+      debug("_respondToQuery Could not find service (key=" + serviceKey + ")");
+      return;
+    }
+
+    DEBUG && debug('_respondToQuery(): key=' + serviceKey + ': SENDING RESPONSE');
+    this._advertiseServiceHelper(publishedService, {address,port});
+  }
+
+  _advertiseService(serviceKey, firstAdv) {
+    DEBUG && debug('_advertiseService(): key=' + serviceKey);
+    let publishedService = this._services.get(serviceKey);
+    if (!publishedService) {
+      debug("_advertiseService Could not find service to advertise (key=" + serviceKey + ")");
+      return;
+    }
+
+    publishedService.advertiseTimer = undefined;
+
+    this._advertiseServiceHelper(publishedService, null).then(() => {
+      // If first advertisement, re-advertise in 1 second.
+      // Otherwise, set the lastAdvertised time.
+      if (firstAdv) {
+        publishedService.advertiseTimer = setTimeout(() => {
+          this._advertiseService(serviceKey)
+        }, 1000);
+      } else {
+        publishedService.lastAdvertised = Date.now();
+        this._checkStartBroadcastTimer();
+      }
+    });
+  }
+
+  _advertiseServiceHelper(svc, target) {
+    if (!target) {
+      target = {address:MDNS_MULTICAST_GROUP, port:MDNS_PORT};
+    }
+
+    return this._getSockets().then((sockets) => {
+      sockets.forEach((socket, address) => {
+        if (svc.address == "0.0.0.0" || address == svc.address)
+        {
+          let packet = this._makeServicePacket(svc, [address]);
+          let data = packet.serialize();
+          try {
+            socket.send(target.address, target.port, data, data.length);
+          } catch (err) {
+            DEBUG && debug("Failed to send packet to "
+                            + target.address + ":" + target.port);
+          }
+        }
+      });
+    });
+  }
+
+  _cancelBroadcastTimer() {
+    if (!this._broadcastTimer) {
+      return;
+    }
+    clearTimeout(this._broadcastTimer);
+    this._broadcastTimer = undefined;
+  }
+
+  _checkStartBroadcastTimer() {
+    DEBUG && debug("_checkStartBroadcastTimer()");
+    // Cancel any existing broadcasting timer.
+    this._cancelBroadcastTimer();
+
+    let now = Date.now();
+
+    // Go through services and find services to broadcast.
+    let bcastServices = [];
+    let nextBcastWait = undefined;
+    for (let [serviceKey, publishedService] of this._services) {
+      // if lastAdvertised is undefined, service hasn't finished it's initial
+      // two broadcasts.
+      if (publishedService.lastAdvertised === undefined) {
+        continue;
+      }
+
+      // Otherwise, check lastAdvertised against now.
+      let msSinceAdv = now - publishedService.lastAdvertised;
+
+      // If msSinceAdv is more than 90% of the way to the TTL, advertise now.
+      if (msSinceAdv > (DEFAULT_TTL * 1000 * 0.9)) {
+        bcastServices.push(publishedService);
+        continue;
+      }
+
+      // Otherwise, calculate the next time to advertise for this service.
+      // We set that at 95% of the time to the TTL expiry.
+      let nextAdvWait = (DEFAULT_TTL * 1000 * 0.95) - msSinceAdv;
+      if (nextBcastWait === undefined || nextBcastWait > nextAdvWait) {
+        nextBcastWait = nextAdvWait;
+      }
+    }
+
+    // Schedule an immediate advertisement of all services to be advertised now.
+    for (let svc of bcastServices) {
+        svc.advertiseTimer = setTimeout(() => this._advertiseService(svc.key));
+    }
+
+    // Schedule next broadcast check for the next bcast time.
+    if (nextBcastWait !== undefined) {
+      DEBUG && debug("_checkStartBroadcastTimer(): Scheduling next check in " + nextBcastWait + "ms");
+      this._broadcastTimer = setTimeout(() => this._checkStartBroadcastTimer(), nextBcastWait);
+    }
+  }
+
+  _query(name) {
+    DEBUG && debug('query("' + name + '")');
+    let packet = new DNSPacket();
+    packet.setFlag('QR', DNS_QUERY_RESPONSE_CODES.QUERY);
+
+    // PTR Record
+    packet.addRecord('QD', new DNSRecord({
+      name: name,
+      recordType: DNS_RECORD_TYPES.PTR,
+      classCode: DNS_CLASS_CODES.IN,
+      cacheFlush: true
+    }));
+
+    let data = packet.serialize();
+
+    // Initialize the broadcast receiver socket in case it
+    // hasn't already been started so we can listen for
+    // multicast queries/announcements on all interfaces.
+    this._getBroadcastReceiverSocket();
+
+    this._getQuerySocket().then((querySocket) => {
+      DEBUG && debug('sending query on query socket ("' + name + '")');
+      querySocket.send(MDNS_MULTICAST_GROUP, MDNS_PORT, data, data.length);
+    });
+
+    // Automatically announce previously-discovered
+    // services that match and haven't expired yet.
+    setTimeout(() => {
+      DEBUG && debug('announcing previously discovered services ("' + name + '")');
+      let { serviceType } = _parseServiceDomainName(name);
+
+      this._clearExpiredDiscoveries();
+      this._discovered.forEach((discovery, key) => {
+        let serviceInfo = discovery.serviceInfo;
+        if (serviceInfo.serviceType !== serviceType) {
+          return;
+        }
+
+        let listeners = this._listeners.get(serviceInfo.serviceType) || [];
+        listeners.forEach((listener) => {
+          listener.onServiceFound(serviceInfo);
+        });
+      });
+    });
+  }
+
+  _clearExpiredDiscoveries() {
+    this._discovered.forEach((discovery, key) => {
+      if (discovery.expireTime < Date.now()) {
+        this._discovered.delete(key);
+        return;
+      }
+    });
+  }
+
+  _handleQueryPacket(packet, message) {
+    packet.getRecords(['QD']).forEach((record) => {
+      // Don't respond if the query's class code is not IN or ANY.
+      if (record.classCode !== DNS_CLASS_CODES.IN &&
+          record.classCode !== DNS_CLASS_CODES.ANY) {
+        return;
+      }
+
+      // Don't respond if the query's record type is not PTR or ANY.
+      if (record.recordType !== DNS_RECORD_TYPES.PTR &&
+          record.recordType !== DNS_RECORD_TYPES.ANY) {
+        return;
+      }
+
+      for (let [serviceKey, publishedService] of this._services) {
+        DEBUG && debug("_handleQueryPacket: " + packet.toJSON());
+        if (publishedService.ptrMatch(record.name)) {
+          this._respondToQuery(serviceKey, message);
+        }
+      }
+    });
+  }
+
+  _makeServicePacket(service, addresses) {
+    let packet = new DNSPacket();
+    packet.setFlag('QR', DNS_QUERY_RESPONSE_CODES.RESPONSE);
+    packet.setFlag('AA', DNS_AUTHORITATIVE_ANSWER_CODES.YES);
+
+    let host = service.host || _hostname;
+
+    // e.g.: foo-bar-service._http._tcp.local
+    let serviceDomainName = service.serviceName + '.' + service.serviceType + '.local';
+
+    // PTR Record
+    packet.addRecord('AN', new DNSResourceRecord({
+      name: service.serviceType + '.local', // e.g.: _http._tcp.local
+      recordType: DNS_RECORD_TYPES.PTR,
+      data: serviceDomainName
+    }));
+
+    // SRV Record
+    packet.addRecord('AR', new DNSResourceRecord({
+      name: serviceDomainName,
+      recordType: DNS_RECORD_TYPES.SRV,
+      classCode: DNS_CLASS_CODES.IN,
+      cacheFlush: true,
+      data: {
+        priority: 0,
+        weight: 0,
+        port: service.port,
+        target: host // e.g.: My-Android-Phone.local
+      }
+    }));
+
+    // A Records
+    for (let address of addresses) {
+        packet.addRecord('AR', new DNSResourceRecord({
+          name: host,
+          recordType: DNS_RECORD_TYPES.A,
+          data: address
+        }));
+    }
+
+    // TXT Record
+    packet.addRecord('AR', new DNSResourceRecord({
+      name: serviceDomainName,
+      recordType: DNS_RECORD_TYPES.TXT,
+      classCode: DNS_CLASS_CODES.IN,
+      cacheFlush: true,
+      data: service.serviceAttrs || {}
+    }));
+
+    return packet;
+  }
+
+  _handleResponsePacket(packet, message) {
+    let services = {};
+    let hosts = {};
+
+    let srvRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.SRV);
+    let txtRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.TXT);
+    let ptrRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.PTR);
+    let aRecords = packet.getRecords(['AN', 'AR'], DNS_RECORD_TYPES.A);
+
+    srvRecords.forEach((record) => {
+      let data = record.data || {};
+
+      services[record.name] = {
+        host: data.target,
+        port: data.port,
+        ttl: record.ttl
+      };
+    });
+
+    txtRecords.forEach((record) => {
+      if (!services[record.name]) {
+        return;
+      }
+
+      services[record.name].attributes = record.data;
+    });
+
+    aRecords.forEach((record) => {
+      if (IsIpv4Address(record.data)) {
+        hosts[record.name] = record.data;
+      }
+    });
+
+    ptrRecords.forEach((record) => {
+      let name = record.data;
+      if (!services[name]) {
+        return;
+      }
+
+      let {host, port} = services[name];
+      if (!host || !port) {
+        return;
+      }
+
+      let { serviceName, serviceType, domainName } = _parseServiceDomainName(name);
+      if (!serviceName || !serviceType || !domainName) {
+        return;
+      }
+
+      let address = hosts[host];
+      if (!address) {
+        return;
+      }
+
+      let ttl = services[name].ttl || 0;
+      let serviceInfo = {
+        serviceName: serviceName,
+        serviceType: serviceType,
+        host: host,
+        address: address,
+        port: port,
+        domainName: domainName,
+        attributes: services[name].attributes || {}
+      };
+
+      this._onServiceFound(serviceInfo, ttl);
+    });
+  }
+
+  _onServiceFound(serviceInfo, ttl = 0) {
+    let expireTime = Date.now() + (ttl * 1000);
+    let key = serviceInfo.serviceName + '.' +
+              serviceInfo.serviceType + '.' +
+              serviceInfo.domainName + ' @' +
+              serviceInfo.address + ':' +
+              serviceInfo.port;
+
+    // If this service was already discovered, just update
+    // its expiration time and don't re-emit it.
+    if (this._discovered.has(key)) {
+      this._discovered.get(key).expireTime = expireTime;
+      return;
+    }
+
+    this._discovered.set(key, {
+      serviceInfo: serviceInfo,
+      expireTime: expireTime
+    });
+
+    let listeners = this._listeners.get(serviceInfo.serviceType) || [];
+    listeners.forEach((listener) => {
+      listener.onServiceFound(serviceInfo);
+    });
+
+    DEBUG && debug('_onServiceFound()' + serviceInfo.serviceName);
+  }
+
+  /**
+   * Gets a non-exclusive socket on 0.0.0.0:{random} to send
+   * multicast queries on all interfaces. This socket does
+   * not need to join a multicast group since it is still
+   * able to *send* multicast queries, but it does not need
+   * to *listen* for multicast queries/announcements since
+   * the `_broadcastReceiverSocket` is already handling them.
+   */
+  _getQuerySocket() {
+    return new Promise((resolve, reject) => {
+      if (!this._querySocket) {
+        this._querySocket = _openSocket('0.0.0.0', 0, {
+          onPacketReceived: this._onPacketReceived.bind(this),
+          onStopListening: this._onStopListening.bind(this)
+        });
+      }
+      resolve(this._querySocket);
+    });
+  }
+
+  /**
+   * Gets a non-exclusive socket on 0.0.0.0:5353 to listen
+   * for multicast queries/announcements on all interfaces.
+   * Since this socket needs to listen for multicast queries
+   * and announcements, this socket joins the multicast
+   * group on *all* interfaces (0.0.0.0).
+   */
+  _getBroadcastReceiverSocket() {
+    return new Promise((resolve, reject) => {
+      if (!this._broadcastReceiverSocket) {
+        this._broadcastReceiverSocket = _openSocket('0.0.0.0', MDNS_PORT, {
+          onPacketReceived: this._onPacketReceived.bind(this),
+          onStopListening: this._onStopListening.bind(this)
+        }, /* multicastInterface = */ '0.0.0.0');
+      }
+      resolve(this._broadcastReceiverSocket);
+    });
+  }
+
+  /**
+   * Gets a non-exclusive socket for each interface on
+   * {iface-ip}:5353 for sending query responses as
+   * well as for listening for unicast queries. These
+   * sockets do not need to join a multicast group
+   * since they are still able to *send* multicast
+   * query responses, but they do not need to *listen*
+   * for multicast queries since the `_querySocket` is
+   * already handling them.
+   */
+  _getSockets() {
+    return new Promise((resolve) => {
+      if (this._sockets.size > 0) {
+        resolve(this._sockets);
+        return;
+      }
+
+      Promise.all([getAddresses(), getHostname()]).then(() => {
+        _addresses.forEach((address) => {
+          let socket = _openSocket(address, MDNS_PORT, null);
+          this._sockets.set(address, socket);
+        });
+
+        resolve(this._sockets);
+      });
+    });
+  }
+
+  _checkCloseSockets() {
+    // Nothing to do if no sockets to close.
+    if (this._sockets.size == 0)
+      return;
+
+    // Don't close sockets if discovery listeners are still present.
+    if (this._listeners.size > 0)
+      return;
+
+    // Don't close sockets if advertised services are present.
+    // Since we need to listen for service queries and respond to them.
+    if (this._services.size > 0)
+      return;
+
+    this._closeSockets();
+  }
+
+  _closeSockets() {
+    this._sockets.forEach(socket => socket.close());
+    this._sockets.clear();
+  }
+
+  _onPacketReceived(socket, message) {
+    let packet = DNSPacket.parse(message.rawData);
+
+    switch (packet.getFlag('QR')) {
+      case DNS_QUERY_RESPONSE_CODES.QUERY:
+        this._handleQueryPacket(packet, message);
+        break;
+      case DNS_QUERY_RESPONSE_CODES.RESPONSE:
+        this._handleResponsePacket(packet, message);
+        break;
+      default:
+        break;
+    }
+  }
+
+  _onStopListening(socket, status) {
+    DEBUG && debug('_onStopListening() ' + status);
+  }
+
+  _addServiceListener(serviceType, listener) {
+    let listeners = this._listeners.get(serviceType);
+    if (!listeners) {
+      listeners = [];
+      this._listeners.set(serviceType, listeners);
+    }
+
+    if (!listeners.find(l => l === listener)) {
+      listeners.push(listener);
+    }
+  }
+
+  _removeServiceListener(serviceType, listener) {
+    let listeners = this._listeners.get(serviceType);
+    if (!listeners) {
+      return;
+    }
+
+    let index = listeners.findIndex(l => l === listener);
+    if (index >= 0) {
+      listeners.splice(index, 1);
+    }
+
+    if (listeners.length === 0) {
+      this._listeners.delete(serviceType);
+    }
+  }
+}
+
+let _addresses;
+
+/**
+ * @private
+ */
+function getAddresses() {
+  return new Promise((resolve, reject) => {
+    if (_addresses) {
+      resolve(_addresses);
+      return;
+    }
+
+    networkInfoService.listNetworkAddresses({
+      onListedNetworkAddresses(aAddressArray) {
+        _addresses = aAddressArray.filter((address) => {
+          return address.indexOf('%p2p') === -1 &&  // No WiFi Direct interfaces
+                 address.indexOf(':')    === -1 &&  // XXX: No IPv6 for now
+                 address != "127.0.0.1"             // No ipv4 loopback addresses.
+        });
+
+        DEBUG && debug('getAddresses(): ' + _addresses);
+        resolve(_addresses);
+      },
+
+      onListNetworkAddressesFailed() {
+        DEBUG && debug('getAddresses() FAILED!');
+        resolve([]);
+      }
+    });
+  });
+}
+
+let _hostname;
+
+/**
+ * @private
+ */
+function getHostname() {
+  return new Promise((resolve) => {
+    if (_hostname) {
+      resolve(_hostname);
+      return;
+    }
+
+    networkInfoService.getHostname({
+      onGotHostname(aHostname) {
+        _hostname = aHostname.replace(/\s/g, '-') + '.local';
+
+        DEBUG && debug('getHostname(): ' + _hostname);
+        resolve(_hostname);
+      },
+
+      onGetHostnameFailed() {
+        DEBUG && debug('getHostname() FAILED');
+        resolve('localhost');
+      }
+    });
+  });
+}
+
+/**
+ * Parse fully qualified domain name to service name, instance name,
+ * and domain name. See https://tools.ietf.org/html/rfc6763#section-7.
+ *
+ * Example: 'foo-bar-service._http._tcp.local' -> {
+ *   serviceName: 'foo-bar-service',
+ *   serviceType: '_http._tcp',
+ *   domainName: 'local'
+ * }
+ *
+ * @private
+ */
+function _parseServiceDomainName(serviceDomainName) {
+  let parts = serviceDomainName.split('.');
+  let index = Math.max(parts.lastIndexOf('_tcp'), parts.lastIndexOf('_udp'));
+
+  return {
+    serviceName: parts.splice(0, index - 1).join('.'),
+    serviceType: parts.splice(0, 2).join('.'),
+    domainName: parts.join('.')
+  };
+}
+
+/**
+ * @private
+ */
+function _propertyBagToObject(propBag) {
+  let result = {};
+  if (propBag.QueryInterface) {
+    propBag.QueryInterface(Ci.nsIPropertyBag2);
+    let propEnum = propBag.enumerator;
+    while (propEnum.hasMoreElements()) {
+      let prop = propEnum.getNext().QueryInterface(Ci.nsIProperty);
+      result[prop.name] = prop.value.toString();
+    }
+  } else {
+    for (let name in propBag) {
+      result[name] = propBag[name].toString();
+    }
+  }
+  return result;
+}
+
+/**
+ * @private
+ */
+function _openSocket(addr, port, handler, multicastInterface) {
+  let socket = Cc['@mozilla.org/network/udp-socket;1'].createInstance(Ci.nsIUDPSocket);
+  socket.init2(addr, port, Services.scriptSecurityManager.getSystemPrincipal(), true);
+
+  if (handler) {
+    socket.asyncListen({
+      onPacketReceived: handler.onPacketReceived,
+      onStopListening: handler.onStopListening
+    });
+  }
+
+  if (multicastInterface) {
+    socket.joinMulticast(MDNS_MULTICAST_GROUP, multicastInterface);
+  }
+
+  return socket;
+}
diff --git a/netwerk/dns/mdns/libmdns/moz.build b/netwerk/dns/mdns/libmdns/moz.build
new file mode 100644
index 000000000..d2dca4955
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/moz.build
@@ -0,0 +1,56 @@
+# -*- 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/.
+
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa' or \
+        (CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk' and CONFIG['ANDROID_VERSION'] >= '16'):
+    UNIFIED_SOURCES += [
+        'MDNSResponderOperator.cpp',
+        'MDNSResponderReply.cpp',
+        'nsDNSServiceDiscovery.cpp',
+    ]
+
+    LOCAL_INCLUDES += [
+      '/netwerk/base',
+    ]
+
+    if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':
+        LOCAL_INCLUDES += [
+            '%' + '%s/%s' % (CONFIG['ANDROID_SOURCE'], d) for d in [
+                'external/mdnsresponder/mDNSShared',
+            ]
+        ]
+
+else:
+    EXTRA_COMPONENTS += [
+        'nsDNSServiceDiscovery.js',
+        'nsDNSServiceDiscovery.manifest',
+    ]
+
+    EXTRA_JS_MODULES += [
+        'fallback/DataReader.jsm',
+        'fallback/DataWriter.jsm',
+        'fallback/DNSPacket.jsm',
+        'fallback/DNSRecord.jsm',
+        'fallback/DNSResourceRecord.jsm',
+        'fallback/DNSTypes.jsm',
+        'fallback/MulticastDNS.jsm',
+    ]
+
+    if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
+        EXTRA_JS_MODULES += [
+            'MulticastDNSAndroid.jsm',
+        ]
+
+UNIFIED_SOURCES += [
+    'nsDNSServiceInfo.cpp',
+    'nsMulticastDNSModule.cpp',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+FINAL_LIBRARY = 'xul'
+
+if CONFIG['GNU_CXX']:
+    CXXFLAGS += ['-Wno-error=shadow']
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.cpp b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.cpp
new file mode 100644
index 000000000..8ffa74b71
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.cpp
@@ -0,0 +1,285 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsDNSServiceDiscovery.h"
+#include "MDNSResponderOperator.h"
+#include "nsICancelable.h"
+#include "nsXULAppAPI.h"
+#include "private/pprio.h"
+
+#ifdef MOZ_WIDGET_GONK
+#include <cutils/properties.h>
+#endif // MOZ_WIDGET_GONK
+
+namespace mozilla {
+namespace net {
+
+namespace {
+
+inline void
+StartService()
+{
+#ifdef MOZ_WIDGET_GONK
+  char value[PROPERTY_VALUE_MAX] = { '\0' };
+  property_get("init.svc.mdnsd", value, "");
+
+  if (strcmp(value, "running") == 0) {
+    return;
+  }
+  property_set("ctl.start", "mdnsd");
+#endif // MOZ_WIDGET_GONK
+}
+
+inline void
+StopService()
+{
+#ifdef MOZ_WIDGET_GONK
+  char value[PROPERTY_VALUE_MAX] = { '\0' };
+  property_get("init.svc.mdnsd", value, "");
+
+  if (strcmp(value, "stopped") == 0) {
+    return;
+  }
+  property_set("ctl.stop", "mdnsd");
+#endif // MOZ_WIDGET_GONK
+}
+
+class ServiceCounter
+{
+public:
+  static bool IsServiceRunning()
+  {
+    return !!sUseCount;
+  }
+
+private:
+  static uint32_t sUseCount;
+
+protected:
+  ServiceCounter()
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (!sUseCount++) {
+      StartService();
+    }
+  }
+
+  virtual ~ServiceCounter()
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    if (!--sUseCount) {
+      StopService();
+    }
+  }
+};
+
+uint32_t ServiceCounter::sUseCount = 0;
+
+class DiscoveryRequest final : public nsICancelable
+                             , private ServiceCounter
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICANCELABLE
+
+  explicit DiscoveryRequest(nsDNSServiceDiscovery* aService,
+                            nsIDNSServiceDiscoveryListener* aListener);
+
+private:
+  virtual ~DiscoveryRequest() { Cancel(NS_OK); }
+
+  RefPtr<nsDNSServiceDiscovery> mService;
+  nsIDNSServiceDiscoveryListener* mListener;
+};
+
+NS_IMPL_ISUPPORTS(DiscoveryRequest, nsICancelable)
+
+DiscoveryRequest::DiscoveryRequest(nsDNSServiceDiscovery* aService,
+                                   nsIDNSServiceDiscoveryListener* aListener)
+  : mService(aService)
+  , mListener(aListener)
+{
+}
+
+NS_IMETHODIMP
+DiscoveryRequest::Cancel(nsresult aReason)
+{
+  if (mService) {
+    mService->StopDiscovery(mListener);
+  }
+
+  mService = nullptr;
+  return NS_OK;
+}
+
+class RegisterRequest final : public nsICancelable
+                            , private ServiceCounter
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICANCELABLE
+
+  explicit RegisterRequest(nsDNSServiceDiscovery* aService,
+                           nsIDNSRegistrationListener* aListener);
+
+private:
+  virtual ~RegisterRequest() { Cancel(NS_OK); }
+
+  RefPtr<nsDNSServiceDiscovery> mService;
+  nsIDNSRegistrationListener* mListener;
+};
+
+NS_IMPL_ISUPPORTS(RegisterRequest, nsICancelable)
+
+RegisterRequest::RegisterRequest(nsDNSServiceDiscovery* aService,
+                                 nsIDNSRegistrationListener* aListener)
+  : mService(aService)
+  , mListener(aListener)
+{
+}
+
+NS_IMETHODIMP
+RegisterRequest::Cancel(nsresult aReason)
+{
+  if (mService) {
+    mService->UnregisterService(mListener);
+  }
+
+  mService = nullptr;
+  return NS_OK;
+}
+
+} // namespace anonymous
+
+NS_IMPL_ISUPPORTS(nsDNSServiceDiscovery, nsIDNSServiceDiscovery)
+
+nsDNSServiceDiscovery::~nsDNSServiceDiscovery()
+{
+#ifdef MOZ_WIDGET_GONK
+  StopService();
+#endif
+}
+
+nsresult
+nsDNSServiceDiscovery::Init()
+{
+  if (!XRE_IsParentProcess()) {
+    MOZ_ASSERT(false, "nsDNSServiceDiscovery can only be used in parent process");
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceDiscovery::StartDiscovery(const nsACString& aServiceType,
+                                      nsIDNSServiceDiscoveryListener* aListener,
+                                      nsICancelable** aRetVal)
+{
+  MOZ_ASSERT(aRetVal);
+
+  nsresult rv;
+  if (NS_WARN_IF(NS_FAILED(rv = StopDiscovery(aListener)))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsICancelable> req = new DiscoveryRequest(this, aListener);
+  RefPtr<BrowseOperator> browserOp = new BrowseOperator(aServiceType,
+                                                          aListener);
+  if (NS_WARN_IF(NS_FAILED(rv = browserOp->Start()))) {
+    return rv;
+  }
+
+  mDiscoveryMap.Put(aListener, browserOp);
+
+  req.forget(aRetVal);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceDiscovery::StopDiscovery(nsIDNSServiceDiscoveryListener* aListener)
+{
+  nsresult rv;
+
+  RefPtr<BrowseOperator> browserOp;
+  if (!mDiscoveryMap.Get(aListener, getter_AddRefs(browserOp))) {
+    return NS_OK;
+  }
+
+  browserOp->Cancel(); // cancel non-started operation
+  if (NS_WARN_IF(NS_FAILED(rv = browserOp->Stop()))) {
+    return rv;
+  }
+
+  mDiscoveryMap.Remove(aListener);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceDiscovery::RegisterService(nsIDNSServiceInfo* aServiceInfo,
+                                       nsIDNSRegistrationListener* aListener,
+                                       nsICancelable** aRetVal)
+{
+  MOZ_ASSERT(aRetVal);
+
+  nsresult rv;
+  if (NS_WARN_IF(NS_FAILED(rv = UnregisterService(aListener)))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsICancelable> req = new RegisterRequest(this, aListener);
+  RefPtr<RegisterOperator> registerOp = new RegisterOperator(aServiceInfo,
+                                                               aListener);
+  if (NS_WARN_IF(NS_FAILED(rv = registerOp->Start()))) {
+    return rv;
+  }
+
+  mRegisterMap.Put(aListener, registerOp);
+
+  req.forget(aRetVal);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceDiscovery::UnregisterService(nsIDNSRegistrationListener* aListener)
+{
+  nsresult rv;
+
+  RefPtr<RegisterOperator> registerOp;
+  if (!mRegisterMap.Get(aListener, getter_AddRefs(registerOp))) {
+    return NS_OK;
+  }
+
+  registerOp->Cancel(); // cancel non-started operation
+  if (NS_WARN_IF(NS_FAILED(rv = registerOp->Stop()))) {
+    return rv;
+  }
+
+  mRegisterMap.Remove(aListener);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceDiscovery::ResolveService(nsIDNSServiceInfo* aServiceInfo,
+                                      nsIDNSServiceResolveListener* aListener)
+{
+  if (!ServiceCounter::IsServiceRunning()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv;
+
+  RefPtr<ResolveOperator> resolveOp = new ResolveOperator(aServiceInfo,
+                                                            aListener);
+  if (NS_WARN_IF(NS_FAILED(rv = resolveOp->Start()))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.h b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.h
new file mode 100644
index 000000000..9bf2c798a
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.h
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_netwerk_dns_mdns_libmdns_nsDNSServiceDiscovery_h
+#define mozilla_netwerk_dns_mdns_libmdns_nsDNSServiceDiscovery_h
+
+#include "nsIDNSServiceDiscovery.h"
+#include "nsCOMPtr.h"
+#include "mozilla/RefPtr.h"
+#include "nsRefPtrHashtable.h"
+
+namespace mozilla {
+namespace net {
+
+class BrowseOperator;
+class RegisterOperator;
+
+class nsDNSServiceDiscovery final : public nsIDNSServiceDiscovery
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIDNSSERVICEDISCOVERY
+
+  explicit nsDNSServiceDiscovery() = default;
+
+  /*
+  ** The mDNS service is started on demand. If no one uses, mDNS service will not
+  ** start. Therefore, all operations before service started will fail
+  ** and get error code |kDNSServiceErr_ServiceNotRunning| defined in dns_sd.h.
+  **/
+  nsresult Init();
+
+  nsresult StopDiscovery(nsIDNSServiceDiscoveryListener* aListener);
+  nsresult UnregisterService(nsIDNSRegistrationListener* aListener);
+
+private:
+  virtual ~nsDNSServiceDiscovery();
+
+  nsRefPtrHashtable<nsISupportsHashKey, BrowseOperator> mDiscoveryMap;
+  nsRefPtrHashtable<nsISupportsHashKey, RegisterOperator> mRegisterMap;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif // mozilla_netwerk_dns_mdns_libmdns_nsDNSServiceDiscovery_h
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.js b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.js
new file mode 100644
index 000000000..b94f67297
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.js
@@ -0,0 +1,201 @@
+/* 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/. */
+"use strict";
+
+const { classes: Cc, interfaces: Ci, results: Cr, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/ExtensionUtils.jsm");
+Cu.import('resource://gre/modules/Services.jsm');
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+let { PlatformInfo } = ExtensionUtils;
+
+if (PlatformInfo.os == "android" && !Services.prefs.getBoolPref("network.mdns.use_js_fallback")) {
+  Cu.import("resource://gre/modules/MulticastDNSAndroid.jsm");
+} else {
+  Cu.import("resource://gre/modules/MulticastDNS.jsm");
+}
+
+const DNSSERVICEDISCOVERY_CID = Components.ID("{f9346d98-f27a-4e89-b744-493843416480}");
+const DNSSERVICEDISCOVERY_CONTRACT_ID = "@mozilla.org/toolkit/components/mdnsresponder/dns-sd;1";
+const DNSSERVICEINFO_CONTRACT_ID = "@mozilla.org/toolkit/components/mdnsresponder/dns-info;1";
+
+function log(aMsg) {
+  dump("-*- nsDNSServiceDiscovery.js : " + aMsg + "\n");
+}
+
+function generateUuid() {
+  var uuidGenerator = Components.classes["@mozilla.org/uuid-generator;1"].
+    getService(Ci.nsIUUIDGenerator);
+  return uuidGenerator.generateUUID().toString();
+}
+
+// Helper class to transform return objects to correct type.
+function ListenerWrapper(aListener, aMdns) {
+  this.listener = aListener;
+  this.mdns = aMdns;
+
+  this.discoveryStarting = false;
+  this.stopDiscovery = false;
+
+  this.registrationStarting = false;
+  this.stopRegistration = false;
+
+  this.uuid = generateUuid();
+}
+
+ListenerWrapper.prototype = {
+  // Helper function for transforming an Object into nsIDNSServiceInfo.
+  makeServiceInfo: function (aServiceInfo) {
+    let serviceInfo = Cc[DNSSERVICEINFO_CONTRACT_ID].createInstance(Ci.nsIDNSServiceInfo);
+
+    for (let name of ['host', 'address', 'port', 'serviceName', 'serviceType']) {
+      try {
+        serviceInfo[name] = aServiceInfo[name];
+      } catch (e) {
+        // ignore exceptions
+      }
+    }
+
+    let attributes;
+    try {
+      attributes = _toPropertyBag2(aServiceInfo.attributes);
+    } catch (err) {
+        // Ignore unset attributes in object.
+        log("Caught unset attributes error: " + err + " - " + err.stack);
+        attributes = Cc['@mozilla.org/hash-property-bag;1']
+                        .createInstance(Ci.nsIWritablePropertyBag2);
+    }
+    serviceInfo.attributes = attributes;
+
+    return serviceInfo;
+  },
+
+  /* transparent types */
+  onDiscoveryStarted: function(aServiceType) {
+    this.discoveryStarting = false;
+    this.listener.onDiscoveryStarted(aServiceType);
+
+    if (this.stopDiscovery) {
+      this.mdns.stopDiscovery(aServiceType, this);
+    }
+  },
+  onDiscoveryStopped: function(aServiceType) {
+    this.listener.onDiscoveryStopped(aServiceType);
+  },
+  onStartDiscoveryFailed: function(aServiceType, aErrorCode) {
+    log('onStartDiscoveryFailed: ' + aServiceType + ' (' + aErrorCode + ')');
+    this.discoveryStarting = false;
+    this.stopDiscovery = true;
+    this.listener.onStartDiscoveryFailed(aServiceType, aErrorCode);
+  },
+  onStopDiscoveryFailed: function(aServiceType, aErrorCode) {
+    log('onStopDiscoveryFailed: ' + aServiceType + ' (' + aErrorCode + ')');
+    this.listener.onStopDiscoveryFailed(aServiceType, aErrorCode);
+  },
+
+  /* transform types */
+  onServiceFound: function(aServiceInfo) {
+    this.listener.onServiceFound(this.makeServiceInfo(aServiceInfo));
+  },
+  onServiceLost: function(aServiceInfo) {
+    this.listener.onServiceLost(this.makeServiceInfo(aServiceInfo));
+  },
+  onServiceRegistered: function(aServiceInfo) {
+    this.registrationStarting = false;
+    this.listener.onServiceRegistered(this.makeServiceInfo(aServiceInfo));
+
+    if (this.stopRegistration) {
+      this.mdns.unregisterService(aServiceInfo, this);
+    }
+  },
+  onServiceUnregistered: function(aServiceInfo) {
+    this.listener.onServiceUnregistered(this.makeServiceInfo(aServiceInfo));
+  },
+  onServiceResolved: function(aServiceInfo) {
+    this.listener.onServiceResolved(this.makeServiceInfo(aServiceInfo));
+  },
+
+  onRegistrationFailed: function(aServiceInfo, aErrorCode) {
+    log('onRegistrationFailed: (' + aErrorCode + ')');
+    this.registrationStarting = false;
+    this.stopRegistration = true;
+    this.listener.onRegistrationFailed(this.makeServiceInfo(aServiceInfo), aErrorCode);
+  },
+  onUnregistrationFailed: function(aServiceInfo, aErrorCode) {
+    log('onUnregistrationFailed: (' + aErrorCode + ')');
+    this.listener.onUnregistrationFailed(this.makeServiceInfo(aServiceInfo), aErrorCode);
+  },
+  onResolveFailed: function(aServiceInfo, aErrorCode) {
+    log('onResolveFailed: (' + aErrorCode + ')');
+    this.listener.onResolveFailed(this.makeServiceInfo(aServiceInfo), aErrorCode);
+  }
+};
+
+function nsDNSServiceDiscovery() {
+  log("nsDNSServiceDiscovery");
+  this.mdns = new MulticastDNS();
+}
+
+nsDNSServiceDiscovery.prototype = {
+  classID: DNSSERVICEDISCOVERY_CID,
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference, Ci.nsIDNSServiceDiscovery]),
+
+  startDiscovery: function(aServiceType, aListener) {
+    log("startDiscovery");
+    let listener = new ListenerWrapper(aListener, this.mdns);
+    listener.discoveryStarting = true;
+    this.mdns.startDiscovery(aServiceType, listener);
+
+    return {
+      QueryInterface: XPCOMUtils.generateQI([Ci.nsICancelable]),
+      cancel: (function() {
+        if (this.discoveryStarting || this.stopDiscovery) {
+          this.stopDiscovery = true;
+          return;
+        }
+        this.mdns.stopDiscovery(aServiceType, listener);
+      }).bind(listener)
+    };
+  },
+
+  registerService: function(aServiceInfo, aListener) {
+    log("registerService");
+    let listener = new ListenerWrapper(aListener, this.mdns);
+    listener.registrationStarting = true;
+    this.mdns.registerService(aServiceInfo, listener);
+
+    return {
+      QueryInterface: XPCOMUtils.generateQI([Ci.nsICancelable]),
+      cancel: (function() {
+        if (this.registrationStarting || this.stopRegistration) {
+          this.stopRegistration = true;
+          return;
+        }
+        this.mdns.unregisterService(aServiceInfo, listener);
+      }).bind(listener)
+    };
+  },
+
+  resolveService: function(aServiceInfo, aListener) {
+    log("resolveService");
+    this.mdns.resolveService(aServiceInfo, new ListenerWrapper(aListener));
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([nsDNSServiceDiscovery]);
+
+function _toPropertyBag2(obj)
+{
+  if (obj.QueryInterface) {
+    return obj.QueryInterface(Ci.nsIPropertyBag2);
+  }
+
+  let result = Cc['@mozilla.org/hash-property-bag;1']
+                  .createInstance(Ci.nsIWritablePropertyBag2);
+  for (let name in obj) {
+    result.setPropertyAsAString(name, obj[name]);
+  }
+  return result;
+}
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.manifest b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.manifest
new file mode 100644
index 000000000..c17e719f2
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceDiscovery.manifest
@@ -0,0 +1,3 @@
+# nsDNSServiceDiscovery.js
+component {f9346d98-f27a-4e89-b744-493843416480} nsDNSServiceDiscovery.js
+contract @mozilla.org/toolkit/components/mdnsresponder/dns-sd;1 {f9346d98-f27a-4e89-b744-493843416480}
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.cpp b/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.cpp
new file mode 100644
index 000000000..7c67b49ac
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.cpp
@@ -0,0 +1,209 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsDNSServiceInfo.h"
+#include "nsHashPropertyBag.h"
+#include "nsIProperty.h"
+#include "nsISimpleEnumerator.h"
+#include "nsISupportsImpl.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla {
+namespace net {
+
+NS_IMPL_ISUPPORTS(nsDNSServiceInfo, nsIDNSServiceInfo)
+
+nsDNSServiceInfo::nsDNSServiceInfo(nsIDNSServiceInfo* aServiceInfo)
+{
+  if (NS_WARN_IF(!aServiceInfo)) {
+    return;
+  }
+
+  nsAutoCString str;
+  uint16_t value;
+
+  if (NS_SUCCEEDED(aServiceInfo->GetHost(str))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetHost(str)));
+  }
+  if (NS_SUCCEEDED(aServiceInfo->GetAddress(str))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetAddress(str)));
+  }
+  if (NS_SUCCEEDED(aServiceInfo->GetPort(&value))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetPort(value)));
+  }
+  if (NS_SUCCEEDED(aServiceInfo->GetServiceName(str))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetServiceName(str)));
+  }
+  if (NS_SUCCEEDED(aServiceInfo->GetServiceType(str))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetServiceType(str)));
+  }
+  if (NS_SUCCEEDED(aServiceInfo->GetDomainName(str))) {
+    Unused << NS_WARN_IF(NS_FAILED(SetDomainName(str)));
+  }
+
+  nsCOMPtr<nsIPropertyBag2> attributes; // deep copy
+  if (NS_SUCCEEDED(aServiceInfo->GetAttributes(getter_AddRefs(attributes)))) {
+    nsCOMPtr<nsISimpleEnumerator> enumerator;
+    if (NS_WARN_IF(NS_FAILED(attributes->GetEnumerator(getter_AddRefs(enumerator))))) {
+      return;
+    }
+
+    nsCOMPtr<nsIWritablePropertyBag2> newAttributes = new nsHashPropertyBag();
+
+    bool hasMoreElements;
+    while (NS_SUCCEEDED(enumerator->HasMoreElements(&hasMoreElements)) &&
+           hasMoreElements) {
+      nsCOMPtr<nsISupports> element;
+      Unused <<
+        NS_WARN_IF(NS_FAILED(enumerator->GetNext(getter_AddRefs(element))));
+      nsCOMPtr<nsIProperty> property = do_QueryInterface(element);
+      MOZ_ASSERT(property);
+
+      nsAutoString name;
+      nsCOMPtr<nsIVariant> value;
+      Unused << NS_WARN_IF(NS_FAILED(property->GetName(name)));
+      Unused << NS_WARN_IF(NS_FAILED(property->GetValue(getter_AddRefs(value))));
+      nsAutoCString valueStr;
+      Unused << NS_WARN_IF(NS_FAILED(value->GetAsACString(valueStr)));
+
+      Unused << NS_WARN_IF(NS_FAILED(newAttributes->SetPropertyAsACString(name, valueStr)));
+    }
+
+    Unused << NS_WARN_IF(NS_FAILED(SetAttributes(newAttributes)));
+  }
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetHost(nsACString& aHost)
+{
+  if (!mIsHostSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  aHost = mHost;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetHost(const nsACString& aHost)
+{
+  mHost = aHost;
+  mIsHostSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetAddress(nsACString& aAddress)
+{
+  if (!mIsAddressSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  aAddress = mAddress;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetAddress(const nsACString& aAddress)
+{
+  mAddress = aAddress;
+  mIsAddressSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetPort(uint16_t* aPort)
+{
+  if (NS_WARN_IF(!aPort)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  if (!mIsPortSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  *aPort = mPort;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetPort(uint16_t aPort)
+{
+  mPort = aPort;
+  mIsPortSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetServiceName(nsACString& aServiceName)
+{
+  if (!mIsServiceNameSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  aServiceName = mServiceName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetServiceName(const nsACString& aServiceName)
+{
+  mServiceName = aServiceName;
+  mIsServiceNameSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetServiceType(nsACString& aServiceType)
+{
+  if (!mIsServiceTypeSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  aServiceType = mServiceType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetServiceType(const nsACString& aServiceType)
+{
+  mServiceType = aServiceType;
+  mIsServiceTypeSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetDomainName(nsACString& aDomainName)
+{
+  if (!mIsDomainNameSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  aDomainName = mDomainName;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetDomainName(const nsACString& aDomainName)
+{
+  mDomainName = aDomainName;
+  mIsDomainNameSet = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::GetAttributes(nsIPropertyBag2** aAttributes)
+{
+  if (!mIsAttributesSet) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  nsCOMPtr<nsIPropertyBag2> attributes(mAttributes);
+  attributes.forget(aAttributes);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDNSServiceInfo::SetAttributes(nsIPropertyBag2* aAttributes)
+{
+  mAttributes = aAttributes;
+  mIsAttributesSet = aAttributes ? true : false;
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla
diff --git a/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.h b/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.h
new file mode 100644
index 000000000..cca9c5d01
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsDNSServiceInfo.h
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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_netwerk_dns_mdns_libmdns_nsDNSServiceInfo_h
+#define mozilla_netwerk_dns_mdns_libmdns_nsDNSServiceInfo_h
+
+#include "nsCOMPtr.h"
+#include "nsIDNSServiceDiscovery.h"
+#include "nsIPropertyBag2.h"
+#include "nsString.h"
+
+namespace mozilla {
+namespace net {
+
+class nsDNSServiceInfo final : public nsIDNSServiceInfo
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIDNSSERVICEINFO
+
+  explicit nsDNSServiceInfo() = default;
+  explicit nsDNSServiceInfo(nsIDNSServiceInfo* aServiceInfo);
+
+private:
+  virtual ~nsDNSServiceInfo() = default;
+
+private:
+  nsCString mHost;
+  nsCString mAddress;
+  uint16_t mPort = 0;
+  nsCString mServiceName;
+  nsCString mServiceType;
+  nsCString mDomainName;
+  nsCOMPtr<nsIPropertyBag2> mAttributes;
+
+  bool mIsHostSet = false;
+  bool mIsAddressSet = false;
+  bool mIsPortSet = false;
+  bool mIsServiceNameSet = false;
+  bool mIsServiceTypeSet = false;
+  bool mIsDomainNameSet = false;
+  bool mIsAttributesSet = false;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif // mozilla_netwerk_dns_mdns_libmdns_nsDNSServiceInfo_h
diff --git a/netwerk/dns/mdns/libmdns/nsMulticastDNSModule.cpp b/netwerk/dns/mdns/libmdns/nsMulticastDNSModule.cpp
new file mode 100644
index 000000000..22bad3bc7
--- /dev/null
+++ b/netwerk/dns/mdns/libmdns/nsMulticastDNSModule.cpp
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#if defined(MOZ_WIDGET_COCOA) || (defined(MOZ_WIDGET_GONK) && ANDROID_VERSION >= 16)
+#define ENABLE_DNS_SERVICE_DISCOVERY
+#endif
+
+#include "mozilla/ModuleUtils.h"
+
+#ifdef ENABLE_DNS_SERVICE_DISCOVERY
+#include "nsDNSServiceDiscovery.h"
+#endif
+
+#include "nsDNSServiceInfo.h"
+
+#ifdef ENABLE_DNS_SERVICE_DISCOVERY
+using mozilla::net::nsDNSServiceDiscovery;
+#define DNSSERVICEDISCOVERY_CID \
+  {0x8df43d23, 0xd3f9, 0x4dd5, \
+    { 0xb9, 0x65, 0xde, 0x2c, 0xa3, 0xf6, 0xa4, 0x2c }}
+NS_GENERIC_FACTORY_CONSTRUCTOR_INIT(nsDNSServiceDiscovery, Init)
+NS_DEFINE_NAMED_CID(DNSSERVICEDISCOVERY_CID);
+#endif // ENABLE_DNS_SERVICE_DISCOVERY
+
+using mozilla::net::nsDNSServiceInfo;
+#define DNSSERVICEINFO_CID \
+  {0x14a50f2b, 0x7ff6, 0x48a5, \
+    { 0x88, 0xe3, 0x61, 0x5f, 0xd1, 0x11, 0xf5, 0xd3 }}
+NS_GENERIC_FACTORY_CONSTRUCTOR(nsDNSServiceInfo)
+NS_DEFINE_NAMED_CID(DNSSERVICEINFO_CID);
+
+static const mozilla::Module::CIDEntry knsDNSServiceDiscoveryCIDs[] = {
+#ifdef ENABLE_DNS_SERVICE_DISCOVERY
+  { &kDNSSERVICEDISCOVERY_CID, false, nullptr, nsDNSServiceDiscoveryConstructor },
+#endif
+  { &kDNSSERVICEINFO_CID, false, nullptr, nsDNSServiceInfoConstructor },
+  { nullptr }
+};
+
+static const mozilla::Module::ContractIDEntry knsDNSServiceDiscoveryContracts[] = {
+#ifdef ENABLE_DNS_SERVICE_DISCOVERY
+  { DNSSERVICEDISCOVERY_CONTRACT_ID, &kDNSSERVICEDISCOVERY_CID },
+#endif
+  { DNSSERVICEINFO_CONTRACT_ID, &kDNSSERVICEINFO_CID },
+  { nullptr }
+};
+
+static const mozilla::Module::CategoryEntry knsDNSServiceDiscoveryCategories[] = {
+  { nullptr }
+};
+
+static const mozilla::Module knsDNSServiceDiscoveryModule = {
+  mozilla::Module::kVersion,
+  knsDNSServiceDiscoveryCIDs,
+  knsDNSServiceDiscoveryContracts,
+  knsDNSServiceDiscoveryCategories
+};
+
+NSMODULE_DEFN(nsDNSServiceDiscoveryModule) = &knsDNSServiceDiscoveryModule;
diff --git a/netwerk/dns/mdns/moz.build b/netwerk/dns/mdns/moz.build
new file mode 100644
index 000000000..190bb48e5
--- /dev/null
+++ b/netwerk/dns/mdns/moz.build
@@ -0,0 +1,13 @@
+# -*- 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/.
+
+DIRS += ['libmdns']
+
+XPIDL_SOURCES += [
+    'nsIDNSServiceDiscovery.idl',
+]
+
+XPIDL_MODULE = 'necko_mdns'
diff --git a/netwerk/dns/mdns/nsIDNSServiceDiscovery.idl b/netwerk/dns/mdns/nsIDNSServiceDiscovery.idl
new file mode 100644
index 000000000..23c678ecc
--- /dev/null
+++ b/netwerk/dns/mdns/nsIDNSServiceDiscovery.idl
@@ -0,0 +1,219 @@
+/* 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"
+
+interface nsICancelable;
+interface nsIPropertyBag2;
+
+/**
+ * Service information
+ */
+[scriptable, uuid(670ed0f9-2fa5-4544-bf1e-ea58ac179374)]
+interface nsIDNSServiceInfo : nsISupports
+{
+  /**
+   * The host name of the service. (E.g. "Android.local.")
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute AUTF8String host;
+
+  /**
+   * The IP address of the service.
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute AUTF8String address;
+
+  /**
+   * The port number of the service. (E.g. 80)
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute unsigned short port;
+
+  /**
+   * The service name of the service for display. (E.g. "My TV")
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute AUTF8String serviceName;
+
+  /**
+   * The type of the service. (E.g. "_http._tcp")
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute AUTF8String serviceType;
+
+  /**
+   * The domain name of the service. (E.g. "local.")
+   * @throws NS_ERROR_NOT_INITIALIZED when getting unset value.
+   */
+  attribute AUTF8String domainName;
+
+  /**
+   * The attributes of the service.
+   */
+  attribute nsIPropertyBag2 attributes;
+};
+
+/**
+ * The callback interface for service discovery
+ */
+[scriptable, uuid(3025b7f2-97bb-435b-b43d-26731b3f5fc4)]
+interface nsIDNSServiceDiscoveryListener : nsISupports
+{
+  /**
+   * Callback when the discovery begins.
+   * @param   aServiceType
+   *          the service type of |startDiscovery|.
+   */
+  void onDiscoveryStarted(in AUTF8String aServiceType);
+
+  /**
+   * Callback when the discovery ends.
+   * @param   aServiceType
+   *          the service type of |startDiscovery|.
+   */
+  void onDiscoveryStopped(in AUTF8String aServiceType);
+
+  /**
+   * Callback when the a service is found.
+   * @param   aServiceInfo
+   *          the info about the found service, where |serviceName|, |aServiceType|, and |domainName| are set.
+   */
+  void onServiceFound(in nsIDNSServiceInfo aServiceInfo);
+
+  /**
+   * Callback when the a service is lost.
+   * @param   aServiceInfo
+   *          the info about the lost service, where |serviceName|, |aServiceType|, and |domainName| are set.
+   */
+  void onServiceLost(in nsIDNSServiceInfo aServiceInfo);
+
+  /**
+   * Callback when the discovery cannot start.
+   * @param   aServiceType
+   *          the service type of |startDiscovery|.
+   * @param   aErrorCode
+   *          the error code.
+   */
+  void onStartDiscoveryFailed(in AUTF8String aServiceType, in long aErrorCode);
+
+  /**
+   * Callback when the discovery cannot stop.
+   * @param   aServiceType
+   *          the service type of |startDiscovery|.
+   * @param   aErrorCode
+   *          the error code.
+   */
+  void onStopDiscoveryFailed(in AUTF8String aServiceType, in long aErrorCode);
+};
+
+/**
+ * The callback interface for service registration
+ */
+[scriptable, uuid(e165e4be-abf4-4963-a66d-ed3ca116e5e4)]
+interface nsIDNSRegistrationListener : nsISupports
+{
+  const long ERROR_SERVICE_NOT_RUNNING = -65563;
+
+  /**
+   * Callback when the service is registered successfully.
+   * @param   aServiceInfo
+   *          the info about the registered service,
+   *          where |serviceName|, |aServiceType|, and |domainName| are set.
+   */
+  void onServiceRegistered(in nsIDNSServiceInfo aServiceInfo);
+
+  /**
+   * Callback when the service is unregistered successfully.
+   * @param   aServiceInfo
+   *          the info about the unregistered service.
+   */
+  void onServiceUnregistered(in nsIDNSServiceInfo aServiceInfo);
+
+  /**
+   * Callback when the service cannot be registered.
+   * @param   aServiceInfo
+   *          the info about the service to be registered.
+   * @param   aErrorCode
+   *          the error code.
+   */
+  void onRegistrationFailed(in nsIDNSServiceInfo aServiceInfo, in long aErrorCode);
+
+  /**
+   * Callback when the service cannot be unregistered.
+   * @param   aServiceInfo
+   *          the info about the registered service.
+   * @param   aErrorCode
+   *          the error code.
+   */
+  void onUnregistrationFailed(in nsIDNSServiceInfo aServiceInfo, in long aErrorCode);
+};
+
+/**
+ * The callback interface for service resolve
+ */
+[scriptable, uuid(24ee6408-648e-421d-accf-c6e5adeccf97)]
+interface nsIDNSServiceResolveListener : nsISupports
+{
+  /**
+   * Callback when the service is resolved successfully.
+   * @param   aServiceInfo
+   *          the info about the resolved service, where |host| and |port| are set.
+   */
+  void onServiceResolved(in nsIDNSServiceInfo aServiceInfo);
+
+  /**
+   * Callback when the service cannot be resolved.
+   * @param   aServiceInfo
+   *          the info about the service to be resolved.
+   * @param   aErrorCode
+   *          the error code.
+   */
+  void onResolveFailed(in nsIDNSServiceInfo aServiceInfo, in long aErrorCode);
+};
+
+/**
+ * The interface for DNS service discovery/registration/resolve
+ */
+[scriptable, uuid(6487899b-beb1-455a-ba65-e4fd465066d7)]
+interface nsIDNSServiceDiscovery : nsISupports
+{
+  /**
+   * Browse for instances of a service.
+   * @param   aServiceType
+   *          the service type to be discovered, E.g. "_http._tcp".
+   * @param   aListener
+   *          callback interface for discovery notifications.
+   * @return  An object that can be used to cancel the service discovery.
+   */
+  nsICancelable startDiscovery(in AUTF8String aServiceType, in nsIDNSServiceDiscoveryListener aListener);
+
+  /**
+   * Register a service that is discovered via |startDiscovery| and |resolveService| calls.
+   * @param   aServiceInfo
+   *          the service information to be registered.
+   *          |port| and |aServiceType| are required attributes.
+   * @param   aListener
+   *          callback interface for registration notifications.
+   * @return  An object that can be used to cancel the service registration.
+   */
+  nsICancelable registerService(in nsIDNSServiceInfo aServiceInfo, in nsIDNSRegistrationListener aListener);
+
+  /**
+   * Resolve a service name discovered via |startDiscovery| to a target host name, port number.
+   * @param   aServiceInfo
+   *          the service information to be registered.
+   *          |serviceName|, |aServiceType|, and |domainName| are required attributes as reported to the |onServiceFound| callback.
+   * @param   aListener
+   *          callback interface for registration notifications.
+   */
+  void resolveService(in nsIDNSServiceInfo aServiceInfo, in nsIDNSServiceResolveListener aListener);
+};
+
+%{ C++
+#define DNSSERVICEDISCOVERY_CONTRACT_ID \
+  "@mozilla.org/toolkit/components/mdnsresponder/dns-sd;1"
+#define DNSSERVICEINFO_CONTRACT_ID \
+  "@mozilla.org/toolkit/components/mdnsresponder/dns-info;1"
+%}