Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 964 insertions, 0 deletions

diff --git a/netwerk/base/nsPACMan.cpp b/netwerk/base/nsPACMan.cpp
new file mode 100644
index 0000000000..509c9a3508
--- /dev/null
+++ b/netwerk/base/nsPACMan.cpp
@@ -0,0 +1,964 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "nsPACMan.h"
+
+#include "mozilla/Preferences.h"
+#include "nsContentUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsIAuthPrompt.h"
+#include "nsIDHCPClient.h"
+#include "nsIHttpChannel.h"
+#include "nsIPrefBranch.h"
+#include "nsIPromptFactory.h"
+#include "nsIProtocolProxyService.h"
+#include "nsISystemProxySettings.h"
+#include "nsNetUtil.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Result.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/Telemetry.h"
+
+//-----------------------------------------------------------------------------
+
+namespace mozilla {
+namespace net {
+
+LazyLogModule gProxyLog("proxy");
+
+#undef LOG
+#define LOG(args) MOZ_LOG(gProxyLog, LogLevel::Debug, args)
+#define MOZ_WPAD_URL "http://wpad/wpad.dat"
+#define MOZ_DHCP_WPAD_OPTION 252
+
+// These pointers are declared in nsProtocolProxyService.cpp
+extern const char kProxyType_HTTPS[];
+extern const char kProxyType_DIRECT[];
+
+// The PAC thread does evaluations of both PAC files and
+// nsISystemProxySettings because they can both block the calling thread and we
+// don't want that on the main thread
+
+// Check to see if the underlying request was not an error page in the case of
+// a HTTP request.  For other types of channels, just return true.
+static bool HttpRequestSucceeded(nsIStreamLoader* loader) {
+  nsCOMPtr<nsIRequest> request;
+  loader->GetRequest(getter_AddRefs(request));
+
+  bool result = true;  // default to assuming success
+
+  nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(request);
+  if (httpChannel) {
+    // failsafe
+    Unused << httpChannel->GetRequestSucceeded(&result);
+  }
+
+  return result;
+}
+
+// Read preference setting of extra JavaScript context heap size.
+// PrefService tends to be run on main thread, where ProxyAutoConfig runs on
+// ProxyResolution thread, so it's read here and passed to ProxyAutoConfig.
+static uint32_t GetExtraJSContextHeapSize() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  static int32_t extraSize = -1;
+
+  if (extraSize < 0) {
+    nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+    int32_t value;
+
+    if (prefs &&
+        NS_SUCCEEDED(prefs->GetIntPref(
+            "network.proxy.autoconfig_extra_jscontext_heap_size", &value))) {
+      LOG(("autoconfig_extra_jscontext_heap_size: %d\n", value));
+
+      extraSize = value;
+    }
+  }
+
+  return extraSize < 0 ? 0 : extraSize;
+}
+
+// Read network proxy type from preference
+// Used to verify that the preference is WPAD in nsPACMan::ConfigureWPAD
+nsresult GetNetworkProxyTypeFromPref(int32_t* type) {
+  *type = 0;
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+
+  if (!prefs) {
+    LOG(("Failed to get a preference service object"));
+    return NS_ERROR_FACTORY_NOT_REGISTERED;
+  }
+  nsresult rv = prefs->GetIntPref("network.proxy.type", type);
+  if (NS_FAILED(rv)) {
+    LOG(("Failed to retrieve network.proxy.type from prefs"));
+    return rv;
+  }
+  LOG(("network.proxy.type pref retrieved: %d\n", *type));
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+// The ExecuteCallback runnable is triggered by
+// nsPACManCallback::OnQueryComplete on the Main thread when its completion is
+// discovered on the pac thread
+
+class ExecuteCallback final : public Runnable {
+ public:
+  ExecuteCallback(nsPACManCallback* aCallback, nsresult status)
+      : Runnable("net::ExecuteCallback"),
+        mCallback(aCallback),
+        mStatus(status) {}
+
+  void SetPACString(const nsACString& pacString) { mPACString = pacString; }
+
+  void SetPACURL(const nsACString& pacURL) { mPACURL = pacURL; }
+
+  NS_IMETHOD Run() override {
+    mCallback->OnQueryComplete(mStatus, mPACString, mPACURL);
+    mCallback = nullptr;
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACManCallback> mCallback;
+  nsresult mStatus;
+  nsCString mPACString;
+  nsCString mPACURL;
+};
+
+//-----------------------------------------------------------------------------
+
+// The PAC thread must be deleted from the main thread, this class
+// acts as a proxy to do that, as the PACMan is reference counted
+// and might be destroyed on either thread
+
+class ShutdownThread final : public Runnable {
+ public:
+  explicit ShutdownThread(nsIThread* thread)
+      : Runnable("net::ShutdownThread"), mThread(thread) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    mThread->Shutdown();
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIThread> mThread;
+};
+
+// Dispatch this to wait until the PAC thread shuts down.
+
+class WaitForThreadShutdown final : public Runnable {
+ public:
+  explicit WaitForThreadShutdown(nsPACMan* aPACMan)
+      : Runnable("net::WaitForThreadShutdown"), mPACMan(aPACMan) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    if (mPACMan->mPACThread) {
+      mPACMan->mPACThread->Shutdown();
+      mPACMan->mPACThread = nullptr;
+    }
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+};
+
+//-----------------------------------------------------------------------------
+
+// PACLoadComplete allows the PAC thread to tell the main thread that
+// the javascript PAC file has been installed (perhaps unsuccessfully)
+// and that there is no reason to queue executions anymore
+
+class PACLoadComplete final : public Runnable {
+ public:
+  explicit PACLoadComplete(nsPACMan* aPACMan)
+      : Runnable("net::PACLoadComplete"), mPACMan(aPACMan) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    {
+      auto loader = mPACMan->mLoader.Lock();
+      loader.ref() = nullptr;
+    }
+    mPACMan->PostProcessPendingQ();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+};
+
+//-----------------------------------------------------------------------------
+
+// ConfigureWPADComplete allows the PAC thread to tell the main thread that
+// the URL for the PAC file has been found
+class ConfigureWPADComplete final : public Runnable {
+ public:
+  ConfigureWPADComplete(nsPACMan* aPACMan, const nsACString& aPACURISpec)
+      : Runnable("net::ConfigureWPADComplete"),
+        mPACMan(aPACMan),
+        mPACURISpec(aPACURISpec) {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+    mPACMan->AssignPACURISpec(mPACURISpec);
+    mPACMan->ContinueLoadingAfterPACUriKnown();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+  nsCString mPACURISpec;
+};
+
+//-----------------------------------------------------------------------------
+
+// ExecutePACThreadAction is used to proxy actions from the main
+// thread onto the PAC thread. There are 4 options: process the queue,
+// cancel the queue, query DHCP for the PAC option
+// and setup the javascript context with a new PAC file
+
+class ExecutePACThreadAction final : public Runnable {
+ public:
+  // by default we just process the queue
+  explicit ExecutePACThreadAction(nsPACMan* aPACMan)
+      : Runnable("net::ExecutePACThreadAction"),
+        mPACMan(aPACMan),
+        mCancel(false),
+        mCancelStatus(NS_OK),
+        mSetupPAC(false),
+        mExtraHeapSize(0),
+        mConfigureWPAD(false),
+        mShutdown(false) {}
+
+  void CancelQueue(nsresult status, bool aShutdown) {
+    mCancel = true;
+    mCancelStatus = status;
+    mShutdown = aShutdown;
+  }
+
+  void SetupPAC(const char* data, uint32_t dataLen, const nsACString& pacURI,
+                uint32_t extraHeapSize) {
+    mSetupPAC = true;
+    mSetupPACData.Assign(data, dataLen);
+    mSetupPACURI = pacURI;
+    mExtraHeapSize = extraHeapSize;
+  }
+
+  void ConfigureWPAD() { mConfigureWPAD = true; }
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+    if (mCancel) {
+      mPACMan->CancelPendingQ(mCancelStatus, mShutdown);
+      mCancel = false;
+      return NS_OK;
+    }
+
+    if (mSetupPAC) {
+      mSetupPAC = false;
+
+      nsCOMPtr<nsIEventTarget> target = mPACMan->GetNeckoTarget();
+      mPACMan->mPAC.Init(mSetupPACURI, mSetupPACData, mPACMan->mIncludePath,
+                         mExtraHeapSize, target);
+
+      RefPtr<PACLoadComplete> runnable = new PACLoadComplete(mPACMan);
+      mPACMan->Dispatch(runnable.forget());
+      return NS_OK;
+    }
+
+    if (mConfigureWPAD) {
+      nsAutoCString spec;
+      mConfigureWPAD = false;
+      mPACMan->ConfigureWPAD(spec);
+      RefPtr<ConfigureWPADComplete> runnable =
+          new ConfigureWPADComplete(mPACMan, spec);
+      mPACMan->Dispatch(runnable.forget());
+      return NS_OK;
+    }
+
+    mPACMan->ProcessPendingQ();
+    return NS_OK;
+  }
+
+ private:
+  RefPtr<nsPACMan> mPACMan;
+
+  bool mCancel;
+  nsresult mCancelStatus;
+
+  bool mSetupPAC;
+  uint32_t mExtraHeapSize;
+  nsCString mSetupPACData;
+  nsCString mSetupPACURI;
+  bool mConfigureWPAD;
+  bool mShutdown;
+};
+
+//-----------------------------------------------------------------------------
+
+PendingPACQuery::PendingPACQuery(nsPACMan* pacMan, nsIURI* uri,
+                                 nsPACManCallback* callback, uint32_t flags,
+                                 bool mainThreadResponse)
+    : Runnable("net::PendingPACQuery"),
+      mPort(0),
+      mFlags(flags),
+      mPACMan(pacMan),
+      mCallback(callback),
+      mOnMainThreadOnly(mainThreadResponse) {
+  uri->GetAsciiSpec(mSpec);
+  uri->GetAsciiHost(mHost);
+  uri->GetScheme(mScheme);
+  uri->GetPort(&mPort);
+}
+
+void PendingPACQuery::Complete(nsresult status, const nsACString& pacString) {
+  if (!mCallback) return;
+  RefPtr<ExecuteCallback> runnable = new ExecuteCallback(mCallback, status);
+  runnable->SetPACString(pacString);
+  if (mOnMainThreadOnly)
+    mPACMan->Dispatch(runnable.forget());
+  else
+    runnable->Run();
+}
+
+void PendingPACQuery::UseAlternatePACFile(const nsACString& pacURL) {
+  if (!mCallback) return;
+
+  RefPtr<ExecuteCallback> runnable = new ExecuteCallback(mCallback, NS_OK);
+  runnable->SetPACURL(pacURL);
+  if (mOnMainThreadOnly)
+    mPACMan->Dispatch(runnable.forget());
+  else
+    runnable->Run();
+}
+
+NS_IMETHODIMP
+PendingPACQuery::Run() {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  mPACMan->PostQuery(this);
+  return NS_OK;
+}
+
+//-----------------------------------------------------------------------------
+
+static bool sThreadLocalSetup = false;
+static uint32_t sThreadLocalIndex = 0xdeadbeef;  // out of range
+
+static const char* kPACIncludePath =
+    "network.proxy.autoconfig_url.include_path";
+
+nsPACMan::nsPACMan(nsISerialEventTarget* mainThreadEventTarget)
+    : NeckoTargetHolder(mainThreadEventTarget),
+      mLoader("nsPACMan::mLoader"),
+      mLoadPending(false),
+      mShutdown(false),
+      mLoadFailureCount(0),
+      mInProgress(false),
+      mAutoDetect(false),
+      mWPADOverDHCPEnabled(false),
+      mProxyConfigType(0) {
+  MOZ_ASSERT(NS_IsMainThread(), "pacman must be created on main thread");
+  if (!sThreadLocalSetup) {
+    sThreadLocalSetup = true;
+    PR_NewThreadPrivateIndex(&sThreadLocalIndex, nullptr);
+  }
+  mPAC.SetThreadLocalIndex(sThreadLocalIndex);
+  mIncludePath = Preferences::GetBool(kPACIncludePath, false);
+}
+
+nsPACMan::~nsPACMan() {
+  MOZ_ASSERT(mShutdown, "Shutdown must be called before dtor.");
+
+  if (mPACThread) {
+    if (NS_IsMainThread()) {
+      mPACThread->Shutdown();
+      mPACThread = nullptr;
+    } else {
+      RefPtr<ShutdownThread> runnable = new ShutdownThread(mPACThread);
+      Dispatch(runnable.forget());
+    }
+  }
+
+#ifdef DEBUG
+  {
+    auto loader = mLoader.Lock();
+    NS_ASSERTION(loader.ref() == nullptr, "pac man not shutdown properly");
+  }
+#endif
+
+  NS_ASSERTION(mPendingQ.isEmpty(), "pac man not shutdown properly");
+}
+
+void nsPACMan::Shutdown() {
+  MOZ_ASSERT(NS_IsMainThread(), "pacman must be shutdown on main thread");
+  if (mShutdown) {
+    return;
+  }
+
+  CancelExistingLoad();
+
+  if (mPACThread) {
+    PostCancelPendingQ(NS_ERROR_ABORT, /*aShutdown =*/true);
+
+    // Shutdown is initiated from an observer. We don't want to block the
+    // observer service on thread shutdown so we post a shutdown runnable that
+    // will run after we return instead.
+    RefPtr<WaitForThreadShutdown> runnable = new WaitForThreadShutdown(this);
+    Dispatch(runnable.forget());
+  }
+
+  mShutdown = true;
+}
+
+nsresult nsPACMan::DispatchToPAC(already_AddRefed<nsIRunnable> aEvent,
+                                 bool aSync) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsCOMPtr<nsIRunnable> e(aEvent);
+
+  if (mShutdown) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  // Lazily create the PAC thread. This method is main-thread only so we don't
+  // have to worry about threading issues here.
+  if (!mPACThread) {
+    MOZ_TRY(NS_NewNamedThread("ProxyResolution", getter_AddRefs(mPACThread)));
+  }
+
+  return mPACThread->Dispatch(
+      e.forget(),
+      aSync ? nsIEventTarget::DISPATCH_SYNC : nsIEventTarget::DISPATCH_NORMAL);
+}
+
+nsresult nsPACMan::AsyncGetProxyForURI(nsIURI* uri, nsPACManCallback* callback,
+                                       uint32_t flags,
+                                       bool mainThreadResponse) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  if (mShutdown) return NS_ERROR_NOT_AVAILABLE;
+
+  // Maybe Reload PAC
+  if (!mPACURISpec.IsEmpty() && !mScheduledReload.IsNull() &&
+      TimeStamp::Now() > mScheduledReload) {
+    LOG(("nsPACMan::AsyncGetProxyForURI reload as scheduled\n"));
+
+    LoadPACFromURI(mAutoDetect ? ""_ns : mPACURISpec, false);
+  }
+
+  RefPtr<PendingPACQuery> query =
+      new PendingPACQuery(this, uri, callback, flags, mainThreadResponse);
+
+  if (IsPACURI(uri)) {
+    // deal with this directly instead of queueing it
+    query->Complete(NS_OK, ""_ns);
+    return NS_OK;
+  }
+
+  return DispatchToPAC(query.forget());
+}
+
+nsresult nsPACMan::PostQuery(PendingPACQuery* query) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+
+  if (mShutdown) {
+    query->Complete(NS_ERROR_NOT_AVAILABLE, ""_ns);
+    return NS_OK;
+  }
+
+  // add a reference to the query while it is in the pending list
+  RefPtr<PendingPACQuery> addref(query);
+  mPendingQ.insertBack(addref.forget().take());
+  ProcessPendingQ();
+  return NS_OK;
+}
+
+nsresult nsPACMan::LoadPACFromURI(const nsACString& aSpec) {
+  return LoadPACFromURI(aSpec, true);
+}
+
+nsresult nsPACMan::LoadPACFromURI(const nsACString& aSpec,
+                                  bool aResetLoadFailureCount) {
+  NS_ENSURE_STATE(!mShutdown);
+
+  nsCOMPtr<nsIStreamLoader> loader =
+      do_CreateInstance(NS_STREAMLOADER_CONTRACTID);
+  NS_ENSURE_STATE(loader);
+
+  LOG(("nsPACMan::LoadPACFromURI aSpec: %s, aResetLoadFailureCount: %s\n",
+       aSpec.BeginReading(), aResetLoadFailureCount ? "true" : "false"));
+
+  CancelExistingLoad();
+
+  {
+    auto locked = mLoader.Lock();
+    locked.ref() = loader.forget();
+  }
+  mPACURIRedirectSpec.Truncate();
+  mNormalPACURISpec.Truncate();  // set at load time
+  if (aResetLoadFailureCount) {
+    mLoadFailureCount = 0;
+  }
+  mAutoDetect = aSpec.IsEmpty();
+  mPACURISpec.Assign(aSpec);
+
+  // reset to Null
+  mScheduledReload = TimeStamp();
+
+  // if we're on the main thread here so we can get hold of prefs,
+  // we check that we have WPAD preffed on if we're auto-detecting
+  if (mAutoDetect && NS_IsMainThread()) {
+    nsresult rv = GetNetworkProxyTypeFromPref(&mProxyConfigType);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    if (mProxyConfigType != nsIProtocolProxyService::PROXYCONFIG_WPAD) {
+      LOG(
+          ("LoadPACFromURI - Aborting WPAD autodetection because the pref "
+           "doesn't match anymore"));
+      return NS_BINDING_ABORTED;
+    }
+  }
+  // Since we might get called from nsProtocolProxyService::Init, we need to
+  // post an event back to the main thread before we try to use the IO service.
+  //
+  // But, we need to flag ourselves as loading, so that we queue up any PAC
+  // queries the enter between now and when we actually load the PAC file.
+
+  if (!mLoadPending) {
+    nsCOMPtr<nsIRunnable> runnable = NewRunnableMethod(
+        "nsPACMan::StartLoading", this, &nsPACMan::StartLoading);
+    nsresult rv = NS_IsMainThread()
+                      ? Dispatch(runnable.forget())
+                      : GetCurrentEventTarget()->Dispatch(runnable.forget());
+    if (NS_FAILED(rv)) return rv;
+    mLoadPending = true;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsPACMan::GetPACFromDHCP(nsACString& aSpec) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  if (!mDHCPClient) {
+    LOG(
+        ("nsPACMan::GetPACFromDHCP DHCP option %d query failed because there "
+         "is no DHCP client available\n",
+         MOZ_DHCP_WPAD_OPTION));
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+  nsresult rv;
+  rv = mDHCPClient->GetOption(MOZ_DHCP_WPAD_OPTION, aSpec);
+  if (NS_FAILED(rv)) {
+    LOG((
+        "nsPACMan::GetPACFromDHCP DHCP option %d query failed with result %d\n",
+        MOZ_DHCP_WPAD_OPTION, (uint32_t)rv));
+  } else {
+    LOG(
+        ("nsPACMan::GetPACFromDHCP DHCP option %d query succeeded, finding PAC "
+         "URL %s\n",
+         MOZ_DHCP_WPAD_OPTION, aSpec.BeginReading()));
+  }
+  return rv;
+}
+
+nsresult nsPACMan::ConfigureWPAD(nsACString& aSpec) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+
+  if (mProxyConfigType != nsIProtocolProxyService::PROXYCONFIG_WPAD) {
+    LOG(
+        ("ConfigureWPAD - Aborting WPAD autodetection because the pref "
+         "doesn't match anymore"));
+    return NS_BINDING_ABORTED;
+  }
+
+  aSpec.Truncate();
+  if (mWPADOverDHCPEnabled) {
+    GetPACFromDHCP(aSpec);
+  }
+
+  if (aSpec.IsEmpty()) {
+    // We diverge from the WPAD spec here in that we don't walk the
+    // hosts's FQDN, stripping components until we hit a TLD.  Doing so
+    // is dangerous in the face of an incomplete list of TLDs, and TLDs
+    // get added over time.  We could consider doing only a single
+    // substitution of the first component, if that proves to help
+    // compatibility.
+    aSpec.AssignLiteral(MOZ_WPAD_URL);
+  }
+  return NS_OK;
+}
+
+void nsPACMan::AssignPACURISpec(const nsACString& aSpec) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  mPACURISpec.Assign(aSpec);
+}
+
+void nsPACMan::StartLoading() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  mLoadPending = false;
+
+  {
+    // CancelExistingLoad was called...
+    nsCOMPtr<nsIStreamLoader> loader;
+    {
+      auto locked = mLoader.Lock();
+      loader = locked.ref();
+    }
+    if (!loader) {
+      PostCancelPendingQ(NS_ERROR_ABORT);
+      return;
+    }
+  }
+
+  if (mAutoDetect) {
+    nsresult rv = GetNetworkProxyTypeFromPref(&mProxyConfigType);
+    if (NS_FAILED(rv)) {
+      NS_WARNING(
+          "Could not retrieve Network Proxy Type pref when auto-detecting "
+          "proxy. Halting.");
+      return;
+    }
+    RefPtr<ExecutePACThreadAction> wpadConfigurer =
+        new ExecutePACThreadAction(this);
+    wpadConfigurer->ConfigureWPAD();
+    DispatchToPAC(wpadConfigurer.forget());
+  } else {
+    ContinueLoadingAfterPACUriKnown();
+  }
+}
+
+void nsPACMan::ContinueLoadingAfterPACUriKnown() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsCOMPtr<nsIStreamLoader> loader;
+  {
+    auto locked = mLoader.Lock();
+    loader = locked.ref();
+  }
+
+  // CancelExistingLoad was called...
+  if (!loader) {
+    PostCancelPendingQ(NS_ERROR_ABORT);
+    return;
+  }
+  if (NS_SUCCEEDED(loader->Init(this, nullptr))) {
+    // Always hit the origin server when loading PAC.
+    nsCOMPtr<nsIIOService> ios = do_GetIOService();
+    if (ios) {
+      nsCOMPtr<nsIChannel> channel;
+      nsCOMPtr<nsIURI> pacURI;
+      NS_NewURI(getter_AddRefs(pacURI), mPACURISpec);
+
+      // NOTE: This results in GetProxyForURI being called
+      if (pacURI) {
+        nsresult rv = pacURI->GetSpec(mNormalPACURISpec);
+        MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+        NS_NewChannel(getter_AddRefs(channel), pacURI,
+                      nsContentUtils::GetSystemPrincipal(),
+                      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL,
+                      nsIContentPolicy::TYPE_OTHER,
+                      nullptr,  // nsICookieJarSettings
+                      nullptr,  // PerformanceStorage
+                      nullptr,  // aLoadGroup
+                      nullptr,  // aCallbacks
+                      nsIRequest::LOAD_NORMAL, ios);
+      } else {
+        LOG(("nsPACMan::StartLoading Failed pacspec uri conversion %s\n",
+             mPACURISpec.get()));
+      }
+
+      if (channel) {
+        // allow deprecated HTTP request from SystemPrincipal
+        nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+        loadInfo->SetAllowDeprecatedSystemRequests(true);
+
+        channel->SetLoadFlags(nsIRequest::LOAD_BYPASS_CACHE);
+        channel->SetNotificationCallbacks(this);
+        if (NS_SUCCEEDED(channel->AsyncOpen(loader))) return;
+      }
+    }
+  }
+
+  CancelExistingLoad();
+  PostCancelPendingQ(NS_ERROR_UNEXPECTED);
+}
+
+void nsPACMan::OnLoadFailure() {
+  int32_t minInterval = 5;    // 5 seconds
+  int32_t maxInterval = 300;  // 5 minutes
+
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (prefs) {
+    prefs->GetIntPref("network.proxy.autoconfig_retry_interval_min",
+                      &minInterval);
+    prefs->GetIntPref("network.proxy.autoconfig_retry_interval_max",
+                      &maxInterval);
+  }
+
+  int32_t interval = minInterval << mLoadFailureCount++;  // seconds
+  if (!interval || interval > maxInterval) interval = maxInterval;
+
+  mScheduledReload = TimeStamp::Now() + TimeDuration::FromSeconds(interval);
+
+  LOG(("OnLoadFailure: retry in %d seconds (%d fails)\n", interval,
+       mLoadFailureCount));
+
+  // while we wait for the retry queued members should try direct
+  // even if that means fast failure.
+  PostCancelPendingQ(NS_ERROR_NOT_AVAILABLE);
+}
+
+void nsPACMan::CancelExistingLoad() {
+  nsCOMPtr<nsIStreamLoader> loader;
+  {
+    auto locked = mLoader.Lock();
+    loader.swap(*locked);
+  }
+  if (loader) {
+    nsCOMPtr<nsIRequest> request;
+    loader->GetRequest(getter_AddRefs(request));
+    if (request) {
+      request->Cancel(NS_ERROR_ABORT);
+    }
+  }
+}
+
+void nsPACMan::PostProcessPendingQ() {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+  DispatchToPAC(pending.forget());
+}
+
+void nsPACMan::PostCancelPendingQ(nsresult status, bool aShutdown) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+  RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+  pending->CancelQueue(status, aShutdown);
+  DispatchToPAC(pending.forget());
+}
+
+void nsPACMan::CancelPendingQ(nsresult status, bool aShutdown) {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  RefPtr<PendingPACQuery> query;
+
+  while (!mPendingQ.isEmpty()) {
+    query = dont_AddRef(mPendingQ.popLast());
+    query->Complete(status, ""_ns);
+  }
+
+  if (aShutdown) mPAC.Shutdown();
+}
+
+void nsPACMan::ProcessPendingQ() {
+  MOZ_ASSERT(!NS_IsMainThread(), "wrong thread");
+  while (ProcessPending())
+    ;
+
+  if (mShutdown) {
+    mPAC.Shutdown();
+  } else {
+    // do GC while the thread has nothing pending
+    mPAC.GC();
+  }
+}
+
+// returns true if progress was made by shortening the queue
+bool nsPACMan::ProcessPending() {
+  if (mPendingQ.isEmpty()) return false;
+
+  // queue during normal load, but if we are retrying a failed load then
+  // fast fail the queries
+  if (mInProgress || (IsLoading() && !mLoadFailureCount)) return false;
+
+  RefPtr<PendingPACQuery> query(dont_AddRef(mPendingQ.popFirst()));
+
+  if (mShutdown || IsLoading()) {
+    query->Complete(NS_ERROR_NOT_AVAILABLE, ""_ns);
+    return true;
+  }
+
+  nsAutoCString pacString;
+  bool completed = false;
+  mInProgress = true;
+  nsAutoCString PACURI;
+
+  // first we need to consider the system proxy changing the pac url
+  if (mSystemProxySettings &&
+      NS_SUCCEEDED(mSystemProxySettings->GetPACURI(PACURI)) &&
+      !PACURI.IsEmpty() && !PACURI.Equals(mPACURISpec)) {
+    query->UseAlternatePACFile(PACURI);
+    LOG(("Use PAC from system settings: %s\n", PACURI.get()));
+    completed = true;
+  }
+
+  // now try the system proxy settings for this particular url if
+  // PAC was not specified
+  if (!completed && mSystemProxySettings && PACURI.IsEmpty() &&
+      NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(
+          query->mSpec, query->mScheme, query->mHost, query->mPort,
+          pacString))) {
+    if (query->mFlags & nsIProtocolProxyService::RESOLVE_PREFER_SOCKS_PROXY &&
+        query->mFlags & nsIProtocolProxyService::RESOLVE_PREFER_HTTPS_PROXY) {
+      if (StringBeginsWith(pacString, nsDependentCString(kProxyType_DIRECT),
+                           nsCaseInsensitiveUTF8StringComparator)) {
+        // DIRECT indicates that system proxy settings are not configured to use
+        // SOCKS proxy. Try https proxy as a secondary preferrable proxy. This
+        // is mainly for websocket whose precedence is SOCKS > HTTPS > DIRECT.
+        NS_SUCCEEDED(mSystemProxySettings->GetProxyForURI(
+            query->mSpec, nsDependentCString(kProxyType_HTTPS), query->mHost,
+            query->mPort, pacString));
+      }
+    }
+    LOG(("Use proxy from system settings: %s\n", pacString.get()));
+    query->Complete(NS_OK, pacString);
+    completed = true;
+  }
+
+  // the systemproxysettings didn't complete the resolution. try via PAC
+  if (!completed) {
+    nsresult status =
+        mPAC.GetProxyForURI(query->mSpec, query->mHost, pacString);
+    LOG(("Use proxy from PAC: %s\n", pacString.get()));
+    query->Complete(status, pacString);
+  }
+
+  mInProgress = false;
+  return true;
+}
+
+NS_IMPL_ISUPPORTS(nsPACMan, nsIStreamLoaderObserver, nsIInterfaceRequestor,
+                  nsIChannelEventSink)
+
+NS_IMETHODIMP
+nsPACMan::OnStreamComplete(nsIStreamLoader* loader, nsISupports* context,
+                           nsresult status, uint32_t dataLen,
+                           const uint8_t* data) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  {
+    auto locked = mLoader.Lock();
+    if (locked.ref() != loader) {
+      // If this happens, then it means that LoadPACFromURI was called more
+      // than once before the initial call completed.  In this case, status
+      // should be NS_ERROR_ABORT, and if so, then we know that we can and
+      // should delay any processing.
+      LOG(("OnStreamComplete: called more than once\n"));
+      if (status == NS_ERROR_ABORT) return NS_OK;
+    }
+  }
+
+  LOG(("OnStreamComplete: entry\n"));
+
+  if (NS_SUCCEEDED(status) && HttpRequestSucceeded(loader)) {
+    // Get the URI spec used to load this PAC script.
+    nsAutoCString pacURI;
+    {
+      nsCOMPtr<nsIRequest> request;
+      loader->GetRequest(getter_AddRefs(request));
+      nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+      if (channel) {
+        nsCOMPtr<nsIURI> uri;
+        channel->GetURI(getter_AddRefs(uri));
+        if (uri) uri->GetAsciiSpec(pacURI);
+      }
+    }
+
+    // We succeeded in loading the pac file using a bunch of interfaces that are
+    // main thread only.  Unfortunately, we have to initialize the instance of
+    // the PAC evaluator (NS_PROXYAUTOCONFIG_CONTRACTID) on the PAC thread,
+    // because that's where it will be used.
+    RefPtr<ExecutePACThreadAction> pending = new ExecutePACThreadAction(this);
+    pending->SetupPAC(reinterpret_cast<const char*>(data), dataLen, pacURI,
+                      GetExtraJSContextHeapSize());
+    DispatchToPAC(pending.forget());
+
+    LOG(("OnStreamComplete: process the PAC contents\n"));
+
+    // Even if the PAC file could not be parsed, we did succeed in loading the
+    // data for it.
+    mLoadFailureCount = 0;
+  } else {
+    // We were unable to load the PAC file (presumably because of a network
+    // failure).  Try again a little later.
+    LOG(("OnStreamComplete: unable to load PAC, retry later\n"));
+    OnLoadFailure();
+  }
+
+  if (NS_SUCCEEDED(status))
+    PostProcessPendingQ();
+  else
+    PostCancelPendingQ(status);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsPACMan::GetInterface(const nsIID& iid, void** result) {
+  // In case loading the PAC file requires authentication.
+  if (iid.Equals(NS_GET_IID(nsIAuthPrompt))) {
+    nsCOMPtr<nsIPromptFactory> promptFac =
+        do_GetService("@mozilla.org/prompter;1");
+    NS_ENSURE_TRUE(promptFac, NS_ERROR_NO_INTERFACE);
+    nsresult rv =
+        promptFac->GetPrompt(nullptr, iid, reinterpret_cast<void**>(result));
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_NO_INTERFACE;
+    }
+    return NS_OK;
+  }
+
+  // In case loading the PAC file results in a redirect.
+  if (iid.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    NS_ADDREF_THIS();
+    *result = static_cast<nsIChannelEventSink*>(this);
+    return NS_OK;
+  }
+
+  return NS_ERROR_NO_INTERFACE;
+}
+
+NS_IMETHODIMP
+nsPACMan::AsyncOnChannelRedirect(nsIChannel* oldChannel, nsIChannel* newChannel,
+                                 uint32_t flags,
+                                 nsIAsyncVerifyRedirectCallback* callback) {
+  MOZ_ASSERT(NS_IsMainThread(), "wrong thread");
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIURI> pacURI;
+  if (NS_FAILED((rv = newChannel->GetURI(getter_AddRefs(pacURI))))) return rv;
+
+  rv = pacURI->GetSpec(mPACURIRedirectSpec);
+  if (NS_FAILED(rv)) return rv;
+
+  LOG(("nsPACMan redirect from original %s to redirected %s\n",
+       mPACURISpec.get(), mPACURIRedirectSpec.get()));
+
+  // do not update mPACURISpec - that needs to stay as the
+  // configured URI so that we can determine when the config changes.
+  // However do track the most recent URI in the redirect change
+  // as mPACURIRedirectSpec so that URI can be allowed to bypass
+  // the proxy and actually fetch the pac file.
+
+  callback->OnRedirectVerifyCallback(NS_OK);
+  return NS_OK;
+}
+
+nsresult nsPACMan::Init(nsISystemProxySettings* systemProxySettings) {
+  mSystemProxySettings = systemProxySettings;
+  mDHCPClient = do_GetService(NS_DHCPCLIENT_CONTRACTID);
+  return NS_OK;
+}
+
+}  // namespace net
+}  // namespace mozilla