Bug 939318 - Detect network interface changes on windows properly. r=…

…mcmanus

Now supports IPv6 as well if a new enough windows version is used.
Which notification function to use is detect at run-time.

Now sends CHANGED event if the online interface(s) are different in any
way since it was previously checked and considered UP. CHANGED is sent
before UP in case both are detected.

nIOService: split up the network event receiver function from the
network status init function and have the event receiver act on the
incoming event.

DNSservice: acts on network changes (flushes the host cache)

HttpHandler: acts on network changes

netwerk/base/public/nsINetworkLinkService.idl

@@ -10,7 +10,7 @@
 /**
  * Network link status monitoring service.
  */
-[scriptable, uuid(f7d3be87-7403-4a1e-b89f-2797776e9b08)]
+[scriptable, uuid(2deead82-1d29-45f5-8c59-5dbee477cff8)]
 interface nsINetworkLinkService : nsISupports
 {
   /* Link type constants */
@@ -64,6 +64,11 @@ interface nsINetworkLinkService : nsISupports
  * isLinkUp is now false, linkStatusKnown is true.
  */
 #define NS_NETWORK_LINK_DATA_DOWN    "down"
+/**
+ * isLinkUp is still true, but the network setup is modified.
+ * linkStatusKnown is true.
+ */
+#define NS_NETWORK_LINK_DATA_CHANGED "changed"
 /**
  * linkStatusKnown is now false.
  */

netwerk/base/src/nsIOService.cpp

@@ -60,8 +60,8 @@ using namespace mozilla;
 nsIOService* gIOService = nullptr;
 static bool gHasWarnedUploadChannel2;
 
-// A general port blacklist.  Connections to these ports will not be allowed unless 
-// the protocol overrides.
+// A general port blacklist.  Connections to these ports will not be allowed
+// unless the protocol overrides.
 //
 // TODO: I am sure that there are more ports to be added.  
 //       This cut is based on the classic mozilla codebase
@@ -265,10 +265,9 @@ nsIOService::InitializeNetworkLinkService()
         // so let's cross our fingers!
         mManageOfflineStatus = false;
     }
-
 
     if (mManageOfflineStatus)
-        TrackNetworkLinkStatusForOffline();
+        OnNetworkLinkEvent(NS_NETWORK_LINK_DATA_UNKNOWN);
     else
         SetOffline(false);
 
@@ -922,7 +921,7 @@ nsIOService::Observe(nsISupports *subject,
         if (mOfflineForProfileChange) {
             mOfflineForProfileChange = false;
             if (!mManageOfflineStatus ||
-                NS_FAILED(TrackNetworkLinkStatusForOffline())) {
+                NS_FAILED(OnNetworkLinkEvent(NS_NETWORK_LINK_DATA_UNKNOWN))) {
                 SetOffline(false);
             }
         } 
@@ -952,11 +951,11 @@ nsIOService::Observe(nsISupports *subject,
         mProxyService = nullptr;
     }
     else if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
-        if (!mOfflineForProfileChange && mManageOfflineStatus) {
-            TrackNetworkLinkStatusForOffline();
+        if (!mOfflineForProfileChange) {
+            OnNetworkLinkEvent(NS_ConvertUTF16toUTF8(data).get());
         }
     }
-    
+
     return NS_OK;
 }
 
@@ -1054,24 +1053,25 @@ nsIOService::NewSimpleNestedURI(nsIURI* aURI, nsIURI** aResult)
 }
 
 NS_IMETHODIMP
-nsIOService::SetManageOfflineStatus(bool aManage) {
+nsIOService::SetManageOfflineStatus(bool aManage)
+{
     nsresult rv = NS_OK;
 
     // SetManageOfflineStatus must throw when we fail to go from non-managed
-    // to managed.  Usually because there is no link monitoring service 
-    // available.  Failure to do this switch is detected by a failure of 
-    // TrackNetworkLinkStatusForOffline().  When there is no network link 
-    // available during call to InitializeNetworkLinkService(), application is
-    // put to offline mode.  And when we change mMangeOfflineStatus to false 
-    // on the next line we get stuck on being offline even though the link 
-    // becomes later available.
+    // to managed.  Usually because there is no link monitoring service
+    // available.  Failure to do this switch is detected by a failure of
+    // OnNetworkLinkEvent().  When there is no network link available during
+    // call to InitializeNetworkLinkService(), application is put to offline
+    // mode.  And when we change mMangeOfflineStatus to false on the next line
+    // we get stuck on being offline even though the link becomes later
+    // available.
     bool wasManaged = mManageOfflineStatus;
     mManageOfflineStatus = aManage;
 
     InitializeNetworkLinkService();
 
     if (mManageOfflineStatus && !wasManaged) {
-        rv = TrackNetworkLinkStatusForOffline();
+        rv = OnNetworkLinkEvent(NS_NETWORK_LINK_DATA_UNKNOWN);
         if (NS_FAILED(rv))
             mManageOfflineStatus = false;
     }
@@ -1084,41 +1084,57 @@ nsIOService::GetManageOfflineStatus(bool* aManage) {
     return NS_OK;
 }
 
+// input argument 'data' is already UTF8'ed
 nsresult
-nsIOService::TrackNetworkLinkStatusForOffline()
+nsIOService::OnNetworkLinkEvent(const char *data)
 {
-    NS_ASSERTION(mManageOfflineStatus,
-                 "Don't call this unless we're managing the offline status");
     if (!mNetworkLinkService)
         return NS_ERROR_FAILURE;
 
     if (mShutdown)
         return NS_ERROR_NOT_AVAILABLE;
-
-    // check to make sure this won't collide with Autodial
-    if (mSocketTransportService) {
-        bool autodialEnabled = false;
-        mSocketTransportService->GetAutodialEnabled(&autodialEnabled);
-        // If autodialing-on-link-down is enabled, check if the OS auto dial 
-        // option is set to always autodial. If so, then we are 
-        // always up for the purposes of offline management.
-        if (autodialEnabled) {
+
+    if (mManageOfflineStatus)
+        return NS_OK;
+
+    if (!strcmp(data, NS_NETWORK_LINK_DATA_DOWN)) {
+        // check to make sure this won't collide with Autodial
+        if (mSocketTransportService) {
+            bool autodialEnabled = false;
+            mSocketTransportService->GetAutodialEnabled(&autodialEnabled);
+            // If autodialing-on-link-down is enabled, check if the OS auto
+            // dial option is set to always autodial. If so, then we are
+            // always up for the purposes of offline management.
+            if (autodialEnabled) {
 #if defined(XP_WIN)
-            // On Windows, we should first check with the OS
-            // to see if autodial is enabled.  If it is
-            // enabled then we are allowed to manage the
-            // offline state.
-            if(nsNativeConnectionHelper::IsAutodialEnabled()) 
-                return SetOffline(false);
+                // On Windows, we should first check with the OS to see if
+                // autodial is enabled.  If it is enabled then we are allowed
+                // to manage the offline state.
+                if (nsNativeConnectionHelper::IsAutodialEnabled()) {
+                    return SetOffline(false);
+                }
 #else
-            return SetOffline(false);
+                return SetOffline(false);
 #endif
+            }
         }
     }
 
     bool isUp;
-    nsresult rv = mNetworkLinkService->GetIsLinkUp(&isUp);
-    NS_ENSURE_SUCCESS(rv, rv);
+    if (!strcmp(data, NS_NETWORK_LINK_DATA_DOWN)) {
+        isUp = false;
+    } else if (!strcmp(data, NS_NETWORK_LINK_DATA_UP)) {
+        isUp = true;
+    } else if (!strcmp(data, NS_NETWORK_LINK_DATA_CHANGED)) {
+        // CHANGED events are handled by others
+        return NS_OK;
+    } else if (!strcmp(data, NS_NETWORK_LINK_DATA_UNKNOWN)) {
+        nsresult rv = mNetworkLinkService->GetIsLinkUp(&isUp);
+        NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+        NS_WARNING("Unhandled network event!");
+        return NS_OK;
+    }
     return SetOffline(!isUp);
 }
 

netwerk/base/src/nsIOService.h

@@ -81,7 +81,7 @@ class nsIOService MOZ_FINAL : public nsIIOService2
     nsIOService();
     ~nsIOService();
 
-    nsresult TrackNetworkLinkStatusForOffline();
+    nsresult OnNetworkLinkEvent(const char *data);
 
     nsresult GetCachedProtocolHandler(const char *scheme,
                                                   nsIProtocolHandler* *hdlrResult,

netwerk/dns/nsDNSService2.cpp

@@ -30,12 +30,15 @@
 #include "nsCharSeparatedTokenizer.h"
 #include "nsNetAddr.h"
 #include "nsProxyRelease.h"
+#include "nsIObserverService.h"
+#include "nsINetworkLinkService.h"
 
 #include "mozilla/Attributes.h"
 #include "mozilla/VisualEventTracer.h"
 #include "mozilla/net/NeckoCommon.h"
 #include "mozilla/net/ChildDNSService.h"
 #include "mozilla/net/DNSListenerProxy.h"
+#include "mozilla/Services.h"
 
 using namespace mozilla;
 using namespace mozilla::net;
@@ -540,12 +543,13 @@ nsDNSService::Init()
             prefs->AddObserver("network.proxy.type", this, false);
         }
 
-        nsresult rv;
         nsCOMPtr<nsIObserverService> observerService =
-            do_GetService("@mozilla.org/observer-service;1", &rv);
-        if (NS_SUCCEEDED(rv)) {
+            mozilla::services::GetObserverService();
+        if (observerService) {
             observerService->AddObserver(this, "last-pb-context-exited", false);
+            observerService->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
         }
+
     }
 
     nsDNSPrefetch::Initialize(this);
@@ -870,10 +874,21 @@ nsDNSService::GetMyHostName(nsACString &result)
 NS_IMETHODIMP
 nsDNSService::Observe(nsISupports *subject, const char *topic, const char16_t *data)
 {
-    // we are only getting called if a preference has changed. 
+    // We are only getting called if a preference has changed or there's a
+    // network link event.
     NS_ASSERTION(strcmp(topic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0 ||
-        strcmp(topic, "last-pb-context-exited") == 0,
-        "unexpected observe call");
+                 strcmp(topic, "last-pb-context-exited") == 0 ||
+                 strcmp(topic, NS_NETWORK_LINK_TOPIC) == 0,
+                 "unexpected observe call");
+
+    if (!strcmp(topic, NS_NETWORK_LINK_TOPIC)) {
+        nsCString converted = NS_ConvertUTF16toUTF8(data);
+        const char *state = converted.get();
+        if (!strcmp(state, NS_NETWORK_LINK_DATA_CHANGED)) {
+            mResolver->FlushCache();
+        }
+        return NS_OK;
+    }
 
     //
     // Shutdown and this function are both only called on the UI thread, so we don't

netwerk/dns/nsHostResolver.cpp

@@ -478,10 +478,8 @@ nsHostResolver::ClearPendingQueue(PRCList *aPendingQ)
 }
 
 void
-nsHostResolver::Shutdown()
+nsHostResolver::FlushCache()
 {
-    LOG(("Shutting down host resolver.\n"));
-
     PRCList pendingQHigh, pendingQMed, pendingQLow, evictionQ;
     PR_INIT_CLIST(&pendingQHigh);
     PR_INIT_CLIST(&pendingQMed);
@@ -490,23 +488,20 @@ nsHostResolver::Shutdown()
 
     {
         MutexAutoLock lock(mLock);
-
-        mShutdown = true;
-
         MoveCList(mHighQ, pendingQHigh);
         MoveCList(mMediumQ, pendingQMed);
         MoveCList(mLowQ, pendingQLow);
         MoveCList(mEvictionQ, evictionQ);
         mEvictionQSize = 0;
         mPendingCount = 0;
-        
+
         if (mNumIdleThreads)
             mIdleThreadCV.NotifyAll();
-        
+
         // empty host database
         PL_DHashTableEnumerate(&mDB, HostDB_RemoveEntry, nullptr);
     }
-    
+
     ClearPendingQueue(&pendingQHigh);
     ClearPendingQueue(&pendingQMed);
     ClearPendingQueue(&pendingQLow);
@@ -519,6 +514,18 @@ nsHostResolver::Shutdown()
             NS_RELEASE(rec);
         }
     }
+}
+
+void
+nsHostResolver::Shutdown()
+{
+    LOG(("Shutting down host resolver.\n"));
+
+    {
+        MutexAutoLock lock(mLock);
+        mShutdown = true;
+    }
+    FlushCache();
 
 #ifdef NS_BUILD_REFCNT_LOGGING
 

netwerk/dns/nsHostResolver.h

@@ -238,6 +238,11 @@ class nsHostResolver
 
     size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
 
+    /**
+     * Flush the DNS cache.
+     */
+    void FlushCache();
+
 private:
    explicit nsHostResolver(uint32_t maxCacheEntries = 50, uint32_t maxCacheLifetime = 60,
                             uint32_t lifetimeGracePeriod = 0);