Bug 939318 - Have websockets act on network interface changes. r=mcmanus

If there's no outstanding PING, send a new to make sure the connection
is still alive and fine.

Author: bagder

netwerk/protocol/websocket/BaseWebSocketChannel.cpp

@@ -24,6 +24,7 @@ BaseWebSocketChannel::BaseWebSocketChannel()
   , mWasOpened(0)
   , mClientSetPingInterval(0)
   , mClientSetPingTimeout(0)
+  , mPingForced(0)
   , mPingInterval(0)
   , mPingResponseTimeout(10000)
 {

netwerk/protocol/websocket/BaseWebSocketChannel.h

@@ -72,6 +72,7 @@ class BaseWebSocketChannel : public nsIWebSocketChannel,
   uint32_t                        mWasOpened                 : 1;
   uint32_t                        mClientSetPingInterval     : 1;
   uint32_t                        mClientSetPingTimeout      : 1;
+  uint32_t                        mPingForced                : 1;
 
   uint32_t                        mPingInterval;         /* milliseconds */
   uint32_t                        mPingResponseTimeout;  /* milliseconds */

netwerk/protocol/websocket/WebSocketChannel.cpp

@@ -35,6 +35,8 @@
 #include "nsIRandomGenerator.h"
 #include "nsISocketTransport.h"
 #include "nsThreadUtils.h"
+#include "nsINetworkLinkService.h"
+#include "nsIObserverService.h"
 
 #include "nsAutoPtr.h"
 #include "nsNetCID.h"
@@ -85,7 +87,8 @@ NS_IMPL_ISUPPORTS(WebSocketChannel,
                   nsIProtocolProxyCallback,
                   nsIInterfaceRequestor,
                   nsIChannelEventSink,
-                  nsIThreadRetargetableRequest)
+                  nsIThreadRetargetableRequest,
+                  nsIObserver)
 
 // We implement RFC 6455, which uses Sec-WebSocket-Version: 13 on the wire.
 #define SEC_WEBSOCKET_VERSION "13"
@@ -1046,6 +1049,16 @@ WebSocketChannel::WebSocketChannel() :
     LOG(("Failed to initiate dashboard service."));
 
   mSerial = sSerialSeed++;
+
+  // Register for prefs change notifications
+  nsCOMPtr<nsIObserverService> observerService =
+    mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->AddObserver(this, NS_NETWORK_LINK_TOPIC, false);
+  } else {
+    NS_WARNING("failed to get observer service");
+  }
+
 }
 
 WebSocketChannel::~WebSocketChannel()
@@ -1104,6 +1117,55 @@ WebSocketChannel::~WebSocketChannel()
   }
 }
 
+NS_IMETHODIMP
+WebSocketChannel::Observe(nsISupports *subject,
+                          const char *topic,
+                          const char16_t *data)
+{
+  LOG(("WebSocketChannel::Observe [topic=\"%s\"]\n", topic));
+
+  if (strcmp(topic, NS_NETWORK_LINK_TOPIC) == 0) {
+    nsCString converted = NS_ConvertUTF16toUTF8(data);
+    const char *state = converted.get();
+
+    if (strcmp(state, NS_NETWORK_LINK_DATA_CHANGED) == 0) {
+      LOG(("WebSocket: received network CHANGED event"));
+      if (mPingOutstanding) {
+        // If there's an outstanding ping that's expected to get a pong back
+        // we let that do its thing.
+        LOG(("WebSocket: pong already pending"));
+      } else if (!mSocketThread) {
+        // there has not been an asyncopen yet on the object and then we need
+        // no ping.
+        LOG(("WebSocket: early object, no ping needed"));
+      } else {
+        LOG(("nsWebSocketChannel:: Generating Ping as network changed\n"));
+
+        if (mPingForced) {
+          // avoid more than one
+          return NS_OK;
+        }
+        if (!mPingTimer) {
+          // The ping timer is only conditionally running already. If it
+          // wasn't already created do it here.
+          nsresult rv;
+          mPingTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
+          if (NS_FAILED(rv)) {
+            NS_WARNING("unable to create ping timer. Carrying on.");
+          } else {
+            mPingTimer->SetTarget(mSocketThread);
+          }
+        }
+        // Trigger the ping timeout asap to fire off a new ping. Wait just
+        // a little bit to better avoid multi-triggers.
+        mPingForced = 1;
+        mPingTimer->InitWithCallback(this, 200, nsITimer::TYPE_ONE_SHOT);
+      }
+    }
+  }
+  return NS_OK;
+}
+
 void
 WebSocketChannel::Shutdown()
 {
@@ -2623,11 +2685,16 @@ WebSocketChannel::Notify(nsITimer *timer)
     }
 
     if (!mPingOutstanding) {
-      LOG(("nsWebSocketChannel:: Generating Ping\n"));
-      mPingOutstanding = 1;
-      GeneratePing();
-      mPingTimer->InitWithCallback(this, mPingResponseTimeout,
-                                   nsITimer::TYPE_ONE_SHOT);
+      // Allow for the case where a PING was force-sent even though ping
+      // interval isn't enabled. Only issue a new PING if it truly is enabled.
+      if (mPingInterval || mPingForced) {
+        LOG(("nsWebSocketChannel:: Generating Ping\n"));
+        mPingOutstanding = 1;
+        mPingForced = 0;
+        GeneratePing();
+        mPingTimer->InitWithCallback(this, mPingResponseTimeout,
+                                     nsITimer::TYPE_ONE_SHOT);
+      }
     } else {
       LOG(("nsWebSocketChannel:: Timed out Ping\n"));
       mPingTimer = nullptr;

netwerk/protocol/websocket/WebSocketChannel.h

@@ -14,6 +14,7 @@
 #include "nsIAsyncOutputStream.h"
 #include "nsITimer.h"
 #include "nsIDNSListener.h"
+#include "nsIObserver.h"
 #include "nsIProtocolProxyCallback.h"
 #include "nsIChannelEventSink.h"
 #include "nsIHttpChannelInternal.h"
@@ -62,6 +63,7 @@ class WebSocketChannel : public BaseWebSocketChannel,
                          public nsIOutputStreamCallback,
                          public nsITimerCallback,
                          public nsIDNSListener,
+                         public nsIObserver,
                          public nsIProtocolProxyCallback,
                          public nsIInterfaceRequestor,
                          public nsIChannelEventSink
@@ -78,6 +80,7 @@ class WebSocketChannel : public BaseWebSocketChannel,
   NS_DECL_NSIPROTOCOLPROXYCALLBACK
   NS_DECL_NSIINTERFACEREQUESTOR
   NS_DECL_NSICHANNELEVENTSINK
+  NS_DECL_NSIOBSERVER
 
   // nsIWebSocketChannel methods BaseWebSocketChannel didn't implement for us
   //
@@ -160,8 +163,8 @@ class WebSocketChannel : public BaseWebSocketChannel,
 
   inline void ResetPingTimer()
   {
+    mPingOutstanding = 0;
     if (mPingTimer) {
-      mPingOutstanding = 0;
       mPingTimer->SetDelay(mPingInterval);
     }
   }