--- a/dom/network/UDPSocketParent.cpp
+++ b/dom/network/UDPSocketParent.cpp
@@ -10,24 +10,68 @@
 #include "nsIUDPSocket.h"
 #include "nsINetAddr.h"
 #include "mozilla/AppProcessChecker.h"
 #include "mozilla/unused.h"
 #include "mozilla/ipc/InputStreamUtils.h"
 #include "mozilla/net/DNS.h"
 #include "mozilla/net/NeckoCommon.h"
 #include "mozilla/net/PNeckoParent.h"
+#include "nsNetUtil.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/TabParent.h"
 
 namespace mozilla {
 namespace dom {
 
 NS_IMPL_ISUPPORTS(UDPSocketParent, nsIUDPSocketListener)
 
+UDPSocketParent::UDPSocketParent()
+  : mIPCOpen(true)
+{
+  mObserver = new mozilla::net::OfflineObserver(this);
+}
+
 UDPSocketParent::~UDPSocketParent()
 {
+  if (mObserver) {
+    mObserver->RemoveObserver();
+  }
+}
+
+nsresult
+UDPSocketParent::OfflineNotification(nsISupports *aSubject)
+{
+  nsCOMPtr<nsIAppOfflineInfo> info(do_QueryInterface(aSubject));
+  if (!info) {
+    return NS_OK;
+  }
+
+  uint32_t targetAppId = nsIScriptSecurityManager::UNKNOWN_APP_ID;
+  info->GetAppId(&targetAppId);
+
+  // Obtain App ID
+  uint32_t appId = nsIScriptSecurityManager::UNKNOWN_APP_ID;
+  const PContentParent *content = Manager()->Manager();
+  const InfallibleTArray<PBrowserParent*>& browsers = content->ManagedPBrowserParent();
+  if (browsers.Length() > 0) {
+    TabParent *tab = static_cast<TabParent*>(browsers[0]);
+    appId = tab->OwnAppId();
+  }
+
+  if (appId != targetAppId) {
+    return NS_OK;
+  }
+
+  // If the app is offline, close the socket
+  if (mSocket && NS_IsAppOffline(appId)) {
+    mSocket->Close();
+  }
+
+  return NS_OK;
 }
 
 bool
 UDPSocketParent::Init(const nsACString& aFilter)
 {
   if (!aFilter.IsEmpty()) {
     nsAutoCString contractId(NS_NETWORK_UDP_SOCKET_FILTER_HANDLER_PREFIX);
     contractId.Append(aFilter);

--- a/dom/network/UDPSocketParent.h
+++ b/dom/network/UDPSocketParent.h
@@ -6,57 +6,60 @@
 
 #ifndef mozilla_dom_UDPSocketParent_h__
 #define mozilla_dom_UDPSocketParent_h__
 
 #include "mozilla/net/PUDPSocketParent.h"
 #include "nsCOMPtr.h"
 #include "nsIUDPSocket.h"
 #include "nsIUDPSocketFilter.h"
+#include "mozilla/net/OfflineObserver.h"
 
 namespace mozilla {
 namespace dom {
 
 class UDPSocketParent : public mozilla::net::PUDPSocketParent
                       , public nsIUDPSocketListener
+                      , public mozilla::net::DisconnectableParent
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSIUDPSOCKETLISTENER
 
-  UDPSocketParent() :
-    mIPCOpen(true) {}
+  UDPSocketParent();
 
   bool Init(const nsACString& aFilter);
 
   virtual bool RecvBind(const UDPAddressInfo& aAddressInfo,
                         const bool& aAddressReuse, const bool& aLoopback) MOZ_OVERRIDE;
 
   virtual bool RecvOutgoingData(const UDPData& aData, const UDPSocketAddr& aAddr) MOZ_OVERRIDE;
 
   virtual bool RecvClose() MOZ_OVERRIDE;
 
   virtual bool RecvRequestDelete() MOZ_OVERRIDE;
   virtual bool RecvJoinMulticast(const nsCString& aMulticastAddress,
                                  const nsCString& aInterface) MOZ_OVERRIDE;
   virtual bool RecvLeaveMulticast(const nsCString& aMulticastAddress,
                                   const nsCString& aInterface) MOZ_OVERRIDE;
+  virtual nsresult OfflineNotification(nsISupports *) MOZ_OVERRIDE;
 
 private:
   virtual ~UDPSocketParent();
 
   virtual void ActorDestroy(ActorDestroyReason why) MOZ_OVERRIDE;
   void Send(const InfallibleTArray<uint8_t>& aData, const UDPSocketAddr& aAddr);
   void Send(const InputStreamParams& aStream, const UDPSocketAddr& aAddr);
   nsresult BindInternal(const nsCString& aHost, const uint16_t& aPort,
                         const bool& aAddressReuse, const bool& aLoopback);
 
   void FireInternalError(uint32_t aLineNo);
 
   bool mIPCOpen;
   nsCOMPtr<nsIUDPSocket> mSocket;
   nsCOMPtr<nsIUDPSocketFilter> mFilter;
+  nsRefPtr<mozilla::net::OfflineObserver> mObserver;
 };
 
 } // namespace dom
 } // namespace mozilla
 
 #endif // !defined(mozilla_dom_UDPSocketParent_h__)