diff -r 000000000000 -r 6474c204b198 netwerk/dns/ChildDNSService.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netwerk/dns/ChildDNSService.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,231 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/net/ChildDNSService.h"
+#include "nsIDNSListener.h"
+#include "nsNetUtil.h"
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+#include "nsIXPConnect.h"
+#include "nsIPrefService.h"
+#include "nsIProtocolProxyService.h"
+#include "mozilla/net/NeckoChild.h"
+#include "mozilla/net/DNSRequestChild.h"
+#include "mozilla/net/DNSListenerProxy.h"
+
+namespace mozilla {
+namespace net {
+
+//-----------------------------------------------------------------------------
+// ChildDNSService
+//-----------------------------------------------------------------------------
+
+static ChildDNSService *gChildDNSService;
+static const char kPrefNameDisablePrefetch[] = "network.dns.disablePrefetch";
+
+ChildDNSService* ChildDNSService::GetSingleton()
+{
+  MOZ_ASSERT(IsNeckoChild());
+
+  if (!gChildDNSService) {
+    gChildDNSService = new ChildDNSService();
+  }
+
+  NS_ADDREF(gChildDNSService);
+  return gChildDNSService;
+}
+
+NS_IMPL_ISUPPORTS(ChildDNSService,
+                  nsIDNSService,
+                  nsPIDNSService,
+                  nsIObserver)
+
+ChildDNSService::ChildDNSService()
+  : mFirstTime(true)
+  , mOffline(false)
+{
+  MOZ_ASSERT(IsNeckoChild());
+}
+
+ChildDNSService::~ChildDNSService()
+{
+
+}
+
+//-----------------------------------------------------------------------------
+// ChildDNSService::nsIDNSService
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+ChildDNSService::AsyncResolve(const nsACString  &hostname,
+                              uint32_t           flags,
+                              nsIDNSListener    *listener,
+                              nsIEventTarget    *target_,
+                              nsICancelable    **result)
+{
+  NS_ENSURE_TRUE(gNeckoChild != nullptr, NS_ERROR_FAILURE);
+
+  if (mDisablePrefetch && (flags & RESOLVE_SPECULATE)) {
+    return NS_ERROR_DNS_LOOKUP_QUEUE_FULL;
+  }
+
+  // Support apps being 'offline' even if parent is not: avoids DNS traffic by
+  // apps that have been told they are offline.
+  if (mOffline) {
+    flags |= RESOLVE_OFFLINE;
+  }
+
+  // make sure JS callers get notification on the main thread
+  nsCOMPtr<nsIEventTarget> target = target_;
+  nsCOMPtr<nsIXPConnectWrappedJS> wrappedListener = do_QueryInterface(listener);
+  if (wrappedListener && !target) {
+    nsCOMPtr<nsIThread> mainThread;
+    NS_GetMainThread(getter_AddRefs(mainThread));
+    target = do_QueryInterface(mainThread);
+  }
+  if (target) {
+    // Guarantee listener freed on main thread.  Not sure we need this in child
+    // (or in parent in nsDNSService.cpp) but doesn't hurt.
+    listener = new DNSListenerProxy(listener, target);
+  }
+
+  nsRefPtr<DNSRequestChild> childReq =
+    new DNSRequestChild(nsCString(hostname), flags, listener, target);
+
+  childReq->StartRequest();
+
+  childReq.forget(result);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ChildDNSService::CancelAsyncResolve(const nsACString  &aHostname,
+                                    uint32_t           aFlags,
+                                    nsIDNSListener    *aListener,
+                                    nsresult           aReason)
+{
+  if (mDisablePrefetch && (aFlags & RESOLVE_SPECULATE)) {
+    return NS_ERROR_DNS_LOOKUP_QUEUE_FULL;
+  }
+
+  // TODO: keep a hashtable of pending requests, so we can obey cancel semantics
+  // (call OnLookupComplete with aReason).  Also possible we could send IPDL to
+  // parent to cancel.
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+ChildDNSService::Resolve(const nsACString &hostname,
+                         uint32_t          flags,
+                         nsIDNSRecord    **result)
+{
+  // not planning to ever support this, since sync IPDL is evil.
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+ChildDNSService::GetDNSCacheEntries(nsTArray<mozilla::net::DNSCacheEntries> *args)
+{
+  // Only used by networking dashboard, so may not ever need this in child.
+  // (and would provide a way to spy on what hosts other apps are connecting to,
+  // unless we start keeping per-app DNS caches).
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+ChildDNSService::GetMyHostName(nsACString &result)
+{
+  // TODO: get value from parent during PNecko construction?
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+//-----------------------------------------------------------------------------
+// ChildDNSService::nsPIDNSService
+//-----------------------------------------------------------------------------
+
+nsresult
+ChildDNSService::Init()
+{
+  // Disable prefetching either by explicit preference or if a manual proxy
+  // is configured
+  bool disablePrefetch = false;
+  int  proxyType = nsIProtocolProxyService::PROXYCONFIG_DIRECT;
+
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  prefs->GetBoolPref(kPrefNameDisablePrefetch, &disablePrefetch);
+  if (prefs) {
+    prefs->GetIntPref("network.proxy.type", &proxyType);
+    prefs->GetBoolPref(kPrefNameDisablePrefetch, &disablePrefetch);
+  }
+
+  if (mFirstTime) {
+    mFirstTime = false;
+    if (prefs) {
+      prefs->AddObserver(kPrefNameDisablePrefetch, this, false);
+
+      // Monitor these to see if there is a change in proxy configuration
+      // If a manual proxy is in use, disable prefetch implicitly
+      prefs->AddObserver("network.proxy.type", this, false);
+    }
+  }
+
+  mDisablePrefetch = disablePrefetch ||
+                     (proxyType == nsIProtocolProxyService::PROXYCONFIG_MANUAL);
+
+  return NS_OK;
+}
+
+nsresult
+ChildDNSService::Shutdown()
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ChildDNSService::GetPrefetchEnabled(bool *outVal)
+{
+  *outVal = !mDisablePrefetch;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ChildDNSService::SetPrefetchEnabled(bool inVal)
+{
+  mDisablePrefetch = !inVal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ChildDNSService::GetOffline(bool* aResult)
+{
+  *aResult = mOffline;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ChildDNSService::SetOffline(bool value)
+{
+  mOffline = value;
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+// ChildDNSService::nsIObserver
+//-----------------------------------------------------------------------------
+
+NS_IMETHODIMP
+ChildDNSService::Observe(nsISupports *subject, const char *topic,
+                         const char16_t *data)
+{
+  // we are only getting called if a preference has changed.
+  NS_ASSERTION(strcmp(topic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) == 0,
+               "unexpected observe call");
+
+  // Reread prefs
+  Init();
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla