DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (88fe9a3d4522)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
/* -*- 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 "nsIAsyncVerifyRedirectCallback.h"
#include "nsIAuthPrompt.h"
#include "nsIDHCPClient.h"
#include "nsIHttpChannel.h"
#include "nsIPrefService.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"

//-----------------------------------------------------------------------------

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

// 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");
    mPACMan->mLoader = 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,
                                 bool mainThreadResponse)
    : Runnable("net::PendingPACQuery"),
      mPort(0),
      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(nsIEventTarget* mainThreadEventTarget)
    : NeckoTargetHolder(mainThreadEventTarget),
      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());
    }
  }

  NS_ASSERTION(mLoader == nullptr, "pac man not shutdown properly");
  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,
                                       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 ? EmptyCString() : mPACURISpec, false);
  }

  RefPtr<PendingPACQuery> query =
      new PendingPACQuery(this, uri, callback, mainThreadResponse);

  if (IsPACURI(uri)) {
    // deal with this directly instead of queueing it
    query->Complete(NS_OK, EmptyCString());
    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, EmptyCString());
    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();

  mLoader = loader;
  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())
            : GetCurrentThreadEventTarget()->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...
  if (!mLoader) {
    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");

  // CancelExistingLoad was called...
  if (!mLoader) {
    PostCancelPendingQ(NS_ERROR_ABORT);
    return;
  }
  if (NS_SUCCEEDED(mLoader->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_DATA_IS_NULL,
                      nsIContentPolicy::TYPE_OTHER,
                      nullptr,  // nsICookieSettings
                      nullptr,  // PerformanceStorage
                      nullptr,  // aLoadGroup
                      nullptr,  // aCallbacks
                      nsIRequest::LOAD_NORMAL, ios);
      } else {
        LOG(("nsPACMan::StartLoading Failed pacspec uri conversion %s\n",
             mPACURISpec.get()));
      }

      if (channel) {
        channel->SetLoadFlags(nsIRequest::LOAD_BYPASS_CACHE);
        channel->SetNotificationCallbacks(this);
        if (NS_SUCCEEDED(channel->AsyncOpen(mLoader))) 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() {
  if (mLoader) {
    nsCOMPtr<nsIRequest> request;
    mLoader->GetRequest(getter_AddRefs(request));
    if (request) request->Cancel(NS_ERROR_ABORT);
    mLoader = nullptr;
  }
}

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, EmptyCString());
  }

  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, EmptyCString());
    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))) {
    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");
  if (mLoader != 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_FAILURE);
    return promptFac->GetPrompt(nullptr, iid, reinterpret_cast<void**>(result));
  }

  // 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