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 (b6d82b1a6b02)

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059
/* -*- 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 <stdlib.h>
#include <stdio.h>
#include "nsUpdateDriver.h"
#include "nsXULAppAPI.h"
#include "nsAppRunner.h"
#include "nsIWritablePropertyBag.h"
#include "nsIFile.h"
#include "nsVariant.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "prproces.h"
#include "mozilla/Logging.h"
#include "prenv.h"
#include "nsVersionComparator.h"
#include "nsDirectoryServiceDefs.h"
#include "nsThreadUtils.h"
#include "nsIXULAppInfo.h"
#include "mozilla/Preferences.h"
#include "nsPrintfCString.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Printf.h"
#include "mozilla/UniquePtr.h"
#include "nsIObserverService.h"
#include "nsNetCID.h"
#include "mozilla/Services.h"

#ifdef XP_MACOSX
#  include "nsILocalFileMac.h"
#  include "nsCommandLineServiceMac.h"
#  include "MacLaunchHelper.h"
#  include "updaterfileutils_osx.h"
#  include "mozilla/Monitor.h"
#endif

#if defined(XP_WIN)
#  include <direct.h>
#  include <process.h>
#  include <windows.h>
#  include <shlwapi.h>
#  include <strsafe.h>
#  include "commonupdatedir.h"
#  include "nsWindowsHelpers.h"
#  define getcwd(path, size) _getcwd(path, size)
#  define getpid() GetCurrentProcessId()
#elif defined(XP_UNIX)
#  include <unistd.h>
#  include <sys/wait.h>
#endif

using namespace mozilla;

static LazyLogModule sUpdateLog("updatedriver");
#define LOG(args) MOZ_LOG(sUpdateLog, mozilla::LogLevel::Debug, args)

#ifdef XP_WIN
#  define UPDATER_BIN "updater.exe"
#  define MAINTENANCE_SVC_NAME L"MozillaMaintenance"
#elif XP_MACOSX
#  define UPDATER_APP "updater.app"
#  define UPDATER_BIN "org.mozilla.updater"
#else
#  define UPDATER_BIN "updater"
#endif

#ifdef XP_MACOSX
static void UpdateDriverSetupMacCommandLine(int& argc, char**& argv,
                                            bool restart) {
  if (NS_IsMainThread()) {
    CommandLineServiceMac::SetupMacCommandLine(argc, argv, restart);
    return;
  }
  // Bug 1335916: SetupMacCommandLine calls a CoreFoundation function that
  // asserts that it was called from the main thread, so if we are not the main
  // thread, we have to dispatch that call to there. But we also have to get the
  // result from it, so we can't just dispatch and return, we have to wait
  // until the dispatched operation actually completes. So we also set up a
  // monitor to signal us when that happens, and block until then.
  Monitor monitor("nsUpdateDriver SetupMacCommandLine");

  nsresult rv = NS_DispatchToMainThread(NS_NewRunnableFunction(
      "UpdateDriverSetupMacCommandLine",
      [&argc, &argv, restart, &monitor]() -> void {
        CommandLineServiceMac::SetupMacCommandLine(argc, argv, restart);
        MonitorAutoLock(monitor).Notify();
      }));

  if (NS_FAILED(rv)) {
    LOG(
        ("Update driver error dispatching SetupMacCommandLine to main thread: "
         "%d\n",
         rv));
    return;
  }

  // The length of this wait is arbitrary, but should be long enough that having
  // it expire means something is seriously wrong.
  CVStatus status =
      MonitorAutoLock(monitor).Wait(TimeDuration::FromSeconds(60));
  if (status == CVStatus::Timeout) {
    LOG(("Update driver timed out waiting for SetupMacCommandLine\n"));
  }
}
#endif

static nsresult GetCurrentWorkingDir(nsACString& aOutPath) {
  // Cannot use NS_GetSpecialDirectory because XPCOM is not yet initialized.
  // This code is duplicated from xpcom/io/SpecialSystemDirectory.cpp:

  aOutPath.Truncate();

#if defined(XP_WIN)
  wchar_t wpath[MAX_PATH];
  if (!_wgetcwd(wpath, ArrayLength(wpath))) {
    return NS_ERROR_FAILURE;
  }
  CopyUTF16toUTF8(nsDependentString(wpath), aOutPath);
#else
  char path[MAXPATHLEN];
  if (!getcwd(path, ArrayLength(path))) {
    return NS_ERROR_FAILURE;
  }
  aOutPath = path;
#endif

  return NS_OK;
}

/**
 * Get the path to the installation directory. For Mac OS X this will be the
 * bundle directory.
 *
 * @param appDir         the application directory file object
 * @param installDirPath the path to the installation directory
 */
static nsresult GetInstallDirPath(nsIFile* appDir, nsACString& installDirPath) {
  nsresult rv;
#ifdef XP_MACOSX
  nsCOMPtr<nsIFile> parentDir1, parentDir2;
  rv = appDir->GetParent(getter_AddRefs(parentDir1));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = parentDir1->GetParent(getter_AddRefs(parentDir2));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = parentDir2->GetNativePath(installDirPath);
  NS_ENSURE_SUCCESS(rv, rv);
#elif XP_WIN
  nsAutoString installDirPathW;
  rv = appDir->GetPath(installDirPathW);
  NS_ENSURE_SUCCESS(rv, rv);
  installDirPath = NS_ConvertUTF16toUTF8(installDirPathW);
#else
  rv = appDir->GetNativePath(installDirPath);
  NS_ENSURE_SUCCESS(rv, rv);
#endif
  return NS_OK;
}

static bool GetFile(nsIFile* dir, const nsACString& name,
                    nsCOMPtr<nsIFile>& result) {
  nsresult rv;

  nsCOMPtr<nsIFile> file;
  rv = dir->Clone(getter_AddRefs(file));
  if (NS_FAILED(rv)) {
    return false;
  }

  rv = file->AppendNative(name);
  if (NS_FAILED(rv)) {
    return false;
  }

  result = file;
  return true;
}

static bool GetStatusFile(nsIFile* dir, nsCOMPtr<nsIFile>& result) {
  return GetFile(dir, NS_LITERAL_CSTRING("update.status"), result);
}

/**
 * Get the contents of the update.status file when the update.status file can
 * be opened with read and write access. The reason it is opened for both read
 * and write is to prevent trying to update when the user doesn't have write
 * access to the update directory.
 *
 * @param statusFile the status file object.
 * @param buf        the buffer holding the file contents
 *
 * @return true if successful, false otherwise.
 */
template <size_t Size>
static bool GetStatusFileContents(nsIFile* statusFile, char (&buf)[Size]) {
  static_assert(
      Size > 16,
      "Buffer needs to be large enough to hold the known status codes");

  PRFileDesc* fd = nullptr;
  nsresult rv = statusFile->OpenNSPRFileDesc(PR_RDWR, 0660, &fd);
  if (NS_FAILED(rv)) {
    return false;
  }

  const int32_t n = PR_Read(fd, buf, Size);
  PR_Close(fd);

  return (n >= 0);
}

typedef enum {
  eNoUpdateAction,
  ePendingUpdate,
  ePendingService,
  ePendingElevate,
  eAppliedUpdate,
  eAppliedService,
} UpdateStatus;

/**
 * Returns a value indicating what needs to be done in order to handle an
 * update.
 *
 * @param dir the directory in which we should look for an update.status file.
 * @param statusFile the update.status file found in the directory.
 *
 * @return the update action to be performed.
 */
static UpdateStatus GetUpdateStatus(nsIFile* dir,
                                    nsCOMPtr<nsIFile>& statusFile) {
  if (GetStatusFile(dir, statusFile)) {
    char buf[32];
    if (GetStatusFileContents(statusFile, buf)) {
      const char kPending[] = "pending";
      const char kPendingService[] = "pending-service";
      const char kPendingElevate[] = "pending-elevate";
      const char kApplied[] = "applied";
      const char kAppliedService[] = "applied-service";
      if (!strncmp(buf, kPendingElevate, sizeof(kPendingElevate) - 1)) {
        return ePendingElevate;
      }
      if (!strncmp(buf, kPendingService, sizeof(kPendingService) - 1)) {
        return ePendingService;
      }
      if (!strncmp(buf, kPending, sizeof(kPending) - 1)) {
        return ePendingUpdate;
      }
      if (!strncmp(buf, kAppliedService, sizeof(kAppliedService) - 1)) {
        return eAppliedService;
      }
      if (!strncmp(buf, kApplied, sizeof(kApplied) - 1)) {
        return eAppliedUpdate;
      }
    }
  }
  return eNoUpdateAction;
}

static bool GetVersionFile(nsIFile* dir, nsCOMPtr<nsIFile>& result) {
  return GetFile(dir, NS_LITERAL_CSTRING("update.version"), result);
}

// Compares the current application version with the update's application
// version.
static bool IsOlderVersion(nsIFile* versionFile, const char* appVersion) {
  PRFileDesc* fd = nullptr;
  nsresult rv = versionFile->OpenNSPRFileDesc(PR_RDONLY, 0660, &fd);
  if (NS_FAILED(rv)) {
    return true;
  }

  char buf[32];
  const int32_t n = PR_Read(fd, buf, sizeof(buf));
  PR_Close(fd);

  if (n < 0) {
    return false;
  }

  // Trim off the trailing newline
  if (buf[n - 1] == '\n') {
    buf[n - 1] = '\0';
  }

  // If the update xml doesn't provide the application version the file will
  // contain the string "null" and it is assumed that the update is not older.
  const char kNull[] = "null";
  if (strncmp(buf, kNull, sizeof(kNull) - 1) == 0) {
    return false;
  }

  return mozilla::Version(appVersion) > buf;
}

/**
 * Applies, switches, or stages an update.
 *
 * @param greDir       the GRE directory
 * @param updateDir    the update root directory
 * @param appDir       the application directory
 * @param appArgc      the number of args passed to the application
 * @param appArgv      the args passed to the application
 *                     (used for restarting the application when necessary)
 * @param restart      true when a restart is necessary.
 * @param isStaged     true when the update has already been staged
 * @param outpid (out) parameter holding the handle to the updater application
 *                     when staging updates
 */
static void ApplyUpdate(nsIFile* greDir, nsIFile* updateDir, nsIFile* appDir,
                        int appArgc, char** appArgv, bool restart,
                        bool isStaged, ProcessType* outpid) {
  // The following determines the update operation to perform.
  // 1. When restart is false the update will be staged.
  // 2. When restart is true and isStaged is false the update will apply the mar
  //    file to the installation directory.
  // 3. When restart is true and isStaged is true the update will switch the
  //    staged update with the installation directory.

  nsresult rv;

  nsCOMPtr<nsIFile> updater;
  nsAutoCString updaterPath;
  nsAutoCString updateDirPath;
#if defined(XP_WIN)
  // Get an nsIFile reference for the updater in the installation dir.
  if (!GetFile(greDir, NS_LITERAL_CSTRING(UPDATER_BIN), updater)) {
    return;
  }

  // Get the path to the updater.
  nsAutoString updaterPathW;
  rv = updater->GetPath(updaterPathW);
  if (NS_FAILED(rv)) {
    return;
  }
  updaterPath = NS_ConvertUTF16toUTF8(updaterPathW);

  // Get the path to the update dir.
  nsAutoString updateDirPathW;
  rv = updateDir->GetPath(updateDirPathW);
  if (NS_FAILED(rv)) {
    return;
  }
  updateDirPath = NS_ConvertUTF16toUTF8(updateDirPathW);
#elif defined(XP_MACOSX)
  // Get an nsIFile reference for the updater in the installation dir.
  if (!GetFile(appDir, NS_LITERAL_CSTRING(UPDATER_APP), updater)) {
    return;
  }
  rv = updater->AppendNative(NS_LITERAL_CSTRING("Contents"));
  if (NS_FAILED(rv)) {
    return;
  }
  rv = updater->AppendNative(NS_LITERAL_CSTRING("MacOS"));
  if (NS_FAILED(rv)) {
    return;
  }
  rv = updater->AppendNative(NS_LITERAL_CSTRING(UPDATER_BIN));
  if (NS_FAILED(rv)) {
    return;
  }

  // Get the path to the updater.
  rv = updater->GetNativePath(updaterPath);
  if (NS_FAILED(rv)) {
    return;
  }

  // Get the path to the update dir.
  rv = updateDir->GetNativePath(updateDirPath);
  if (NS_FAILED(rv)) {
    return;
  }
#else
  // Get an nsIFile reference for the updater in the installation dir.
  if (!GetFile(greDir, NS_LITERAL_CSTRING(UPDATER_BIN), updater)) {
    return;
  }

  // Get the path to the updater.
  rv = updater->GetNativePath(updaterPath);
  if (NS_FAILED(rv)) {
    return;
  }

  // Get the path to the update dir.
  rv = updateDir->GetNativePath(updateDirPath);
  if (NS_FAILED(rv)) {
    return;
  }
#endif

  // appFilePath and workingDirPath are only used when the application will be
  // restarted.
  nsAutoCString appFilePath;
  nsAutoCString workingDirPath;
  if (restart) {
    // Get the path to the current working directory.
    rv = GetCurrentWorkingDir(workingDirPath);
    if (NS_FAILED(rv)) {
      return;
    }

    // Get the application file path used by the updater to restart the
    // application after the update has finished.
    nsCOMPtr<nsIFile> appFile;
    XRE_GetBinaryPath(getter_AddRefs(appFile));
    if (!appFile) {
      return;
    }

#if defined(XP_WIN)
    nsAutoString appFilePathW;
    rv = appFile->GetPath(appFilePathW);
    if (NS_FAILED(rv)) {
      return;
    }
    appFilePath = NS_ConvertUTF16toUTF8(appFilePathW);
#else
    rv = appFile->GetNativePath(appFilePath);
    if (NS_FAILED(rv)) {
      return;
    }
#endif
  }

  // Get the installation directory path.
  nsAutoCString installDirPath;
  rv = GetInstallDirPath(appDir, installDirPath);
  if (NS_FAILED(rv)) {
    return;
  }

  nsAutoCString applyToDirPath;
  nsCOMPtr<nsIFile> updatedDir;
  if (restart && !isStaged) {
    // The install directory is the same as the apply to directory.
    applyToDirPath.Assign(installDirPath);
  } else {
    // Get the directory where the update is staged or will be staged.
#if defined(XP_MACOSX)
    if (!GetFile(updateDir, NS_LITERAL_CSTRING("Updated.app"), updatedDir)) {
#else
    if (!GetFile(appDir, NS_LITERAL_CSTRING("updated"), updatedDir)) {
#endif
      return;
    }
#if defined(XP_WIN)
    nsAutoString applyToDirPathW;
    rv = updatedDir->GetPath(applyToDirPathW);
    if (NS_FAILED(rv)) {
      return;
    }
    applyToDirPath = NS_ConvertUTF16toUTF8(applyToDirPathW);
#else
    rv = updatedDir->GetNativePath(applyToDirPath);
#endif
  }
  if (NS_FAILED(rv)) {
    return;
  }

  if (restart && isStaged) {
    // When the update should already be staged make sure that the updated
    // directory exists.
    bool updatedDirExists = false;
    if (NS_FAILED(updatedDir->Exists(&updatedDirExists)) || !updatedDirExists) {
      return;
    }
  }

  // On platforms where we are not calling execv, we may need to make the
  // updater executable wait for the calling process to exit.  Otherwise, the
  // updater may have trouble modifying our executable image (because it might
  // still be in use).  This is accomplished by passing our PID to the updater
  // so that it can wait for us to exit.  This is not perfect as there is a race
  // condition that could bite us.  It's possible that the calling process could
  // exit before the updater waits on the specified PID, and in the meantime a
  // new process with the same PID could be created.  This situation is
  // unlikely, however, given the way most operating systems recycle PIDs. We'll
  // take our chances ;-) Construct the PID argument for this process to pass to
  // the updater.
  nsAutoCString pid;
  if (restart) {
#if defined(XP_UNIX) & !defined(XP_MACOSX)
    // When execv is used for an update that requires a restart 0 is passed
    // which is ignored by the updater.
    pid.AssignLiteral("0");
#else
    pid.AppendInt((int32_t)getpid());
#endif
    if (isStaged) {
      // Append a special token to the PID in order to inform the updater that
      // it should replace install with the updated directory.
      pid.AppendLiteral("/replace");
    }
  } else {
    // Signal the updater application that it should stage the update.
    pid.AssignLiteral("-1");
  }

  int argc = 5;
  if (restart) {
    argc = appArgc + 6;
    if (gRestartedByOS) {
      argc += 1;
    }
  }
  char** argv = static_cast<char**>(malloc((argc + 1) * sizeof(char*)));
  if (!argv) {
    return;
  }
  argv[0] = (char*)updaterPath.get();
  argv[1] = (char*)updateDirPath.get();
  argv[2] = (char*)installDirPath.get();
  argv[3] = (char*)applyToDirPath.get();
  argv[4] = (char*)pid.get();
  if (restart && appArgc) {
    argv[5] = (char*)workingDirPath.get();
    argv[6] = (char*)appFilePath.get();
    for (int i = 1; i < appArgc; ++i) {
      argv[6 + i] = appArgv[i];
    }
    if (gRestartedByOS) {
      // We haven't truly started up, restore this argument so that we will have
      // it upon restart.
      argv[6 + appArgc] = const_cast<char*>("-os-restarted");
    }
  }
  argv[argc] = nullptr;

  if (restart && gSafeMode) {
    PR_SetEnv("MOZ_SAFE_MODE_RESTART=1");
  }

  LOG(("spawning updater process [%s]\n", updaterPath.get()));

#if defined(XP_UNIX) && !defined(XP_MACOSX)
  // We use execv to spawn the updater process on all UNIX systems except Mac
  // OSX since it is known to cause problems on the Mac.  Windows has execv, but
  // it is a faked implementation that doesn't really replace the current
  // process. Instead it spawns a new process, so we gain nothing from using
  // execv on Windows.
  if (restart) {
    int execResult = execv(updaterPath.get(), argv);
    free(argv);
    exit(execResult);
  }
  *outpid = fork();
  if (*outpid == -1) {
    free(argv);
    return;
  } else if (*outpid == 0) {
    int execResult = execv(updaterPath.get(), argv);
    free(argv);
    exit(execResult);
  }
#elif defined(XP_WIN)
  if (isStaged) {
    // Launch the updater to replace the installation with the staged updated.
    if (!WinLaunchChild(updaterPathW.get(), argc, argv)) {
      free(argv);
      return;
    }
  } else {
    // Launch the updater to either stage or apply an update.
    if (!WinLaunchChild(updaterPathW.get(), argc, argv, nullptr, outpid)) {
      free(argv);
      return;
    }
  }
#elif defined(XP_MACOSX)
UpdateDriverSetupMacCommandLine(argc, argv, restart);
// We need to detect whether elevation is required for this update. This can
// occur when an admin user installs the application, but another admin
// user attempts to update (see bug 394984).
if (restart && !IsRecursivelyWritable(installDirPath.get())) {
  bool hasLaunched = LaunchElevatedUpdate(argc, argv, outpid);
  free(argv);
  if (!hasLaunched) {
    LOG(("Failed to launch elevated update!"));
    exit(1);
  }
  exit(0);
}

if (isStaged) {
  // Launch the updater to replace the installation with the staged updated.
  LaunchChildMac(argc, argv);
} else {
  // Launch the updater to either stage or apply an update.
  LaunchChildMac(argc, argv, outpid);
}
#else
if (isStaged) {
  // Launch the updater to replace the installation with the staged updated.
  PR_CreateProcessDetached(updaterPath.get(), argv, nullptr, nullptr);
} else {
  // Launch the updater to either stage or apply an update.
  *outpid = PR_CreateProcess(updaterPath.get(), argv, nullptr, nullptr);
}
#endif
  free(argv);
  if (restart) {
    exit(0);
  }
}

/**
 * Wait briefly to see if a process terminates, then return true if it has.
 */
static bool ProcessHasTerminated(ProcessType pt) {
#if defined(XP_WIN)
  if (WaitForSingleObject(pt, 1000)) {
    return false;
  }
  CloseHandle(pt);
  return true;
#elif defined(XP_MACOSX)
  // We're waiting for the process to terminate in LaunchChildMac.
  return true;
#elif defined(XP_UNIX)
  int exitStatus;
  pid_t exited = waitpid(pt, &exitStatus, WNOHANG);
  if (exited == 0) {
    // Process is still running.
    sleep(1);
    return false;
  }
  if (exited == -1) {
    LOG(("Error while checking if the updater process is finished"));
    // This shouldn't happen, but if it does, the updater process is lost to us,
    // so the best we can do is pretend that it's exited.
    return true;
  }
  // If we get here, the process has exited; make sure it exited normally.
  if (WIFEXITED(exitStatus) && (WEXITSTATUS(exitStatus) != 0)) {
    LOG(("Error while running the updater process, check update.log"));
  }
  return true;
#else
  // No way to have a non-blocking implementation on these platforms,
  // because we're using NSPR and it only provides a blocking wait.
  int32_t exitCode;
  PR_WaitProcess(pt, &exitCode);
  if (exitCode != 0) {
    LOG(("Error while running the updater process, check update.log"));
  }
  return true;
#endif
}

nsresult ProcessUpdates(nsIFile* greDir, nsIFile* appDir, nsIFile* updRootDir,
                        int argc, char** argv, const char* appVersion,
                        bool restart, ProcessType* pid) {
  nsresult rv;

  nsCOMPtr<nsIFile> updatesDir;
  rv = updRootDir->Clone(getter_AddRefs(updatesDir));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = updatesDir->AppendNative(NS_LITERAL_CSTRING("updates"));
  NS_ENSURE_SUCCESS(rv, rv);
  rv = updatesDir->AppendNative(NS_LITERAL_CSTRING("0"));
  NS_ENSURE_SUCCESS(rv, rv);

  // Return early since there isn't a valid update when the update application
  // version file doesn't exist or if the update's application version is less
  // than the current application version. The cleanup of the update will happen
  // during post update processing in nsUpdateService.js.
  nsCOMPtr<nsIFile> versionFile;
  if (!GetVersionFile(updatesDir, versionFile) ||
      IsOlderVersion(versionFile, appVersion)) {
    return NS_OK;
  }

  nsCOMPtr<nsIFile> statusFile;
  UpdateStatus status = GetUpdateStatus(updatesDir, statusFile);
  switch (status) {
    case ePendingUpdate:
    case ePendingService: {
      ApplyUpdate(greDir, updatesDir, appDir, argc, argv, restart, false, pid);
      break;
    }
    case eAppliedUpdate:
    case eAppliedService:
      // An update was staged and needs to be switched so the updated
      // application is used.
      ApplyUpdate(greDir, updatesDir, appDir, argc, argv, restart, true, pid);
      break;
    case ePendingElevate:
      // No action should be performed since the user hasn't opted into
      // elevating for the update so continue application startup.
    case eNoUpdateAction:
      // We don't need to do any special processing here, we'll just continue to
      // startup the application.
      break;
  }

  return NS_OK;
}

NS_IMPL_ISUPPORTS(nsUpdateProcessor, nsIUpdateProcessor)

nsUpdateProcessor::nsUpdateProcessor() : mUpdaterPID(0) {}

nsUpdateProcessor::~nsUpdateProcessor() {}

NS_IMETHODIMP
nsUpdateProcessor::ProcessUpdate() {
  nsresult rv;

  nsCOMPtr<nsIProperties> ds =
      do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIFile> exeFile;
  rv = ds->Get(XRE_EXECUTABLE_FILE, NS_GET_IID(nsIFile),
               getter_AddRefs(exeFile));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIFile> appDir;
  rv = exeFile->GetParent(getter_AddRefs(appDir));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIFile> greDir;
  rv = ds->Get(NS_GRE_DIR, NS_GET_IID(nsIFile), getter_AddRefs(greDir));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIFile> updRoot;
  rv = ds->Get(XRE_UPDATE_ROOT_DIR, NS_GET_IID(nsIFile),
               getter_AddRefs(updRoot));
  NS_ASSERTION(NS_SUCCEEDED(rv), "Can't get the UpdRootD dir");

  // XRE_UPDATE_ROOT_DIR should not fail but if it does fallback to the
  // application directory just to be safe.
  if (NS_FAILED(rv)) {
    rv = appDir->Clone(getter_AddRefs(updRoot));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsCOMPtr<nsIXULAppInfo> appInfo =
      do_GetService("@mozilla.org/xre/app-info;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoCString appVersion;
  rv = appInfo->GetVersion(appVersion);
  NS_ENSURE_SUCCESS(rv, rv);

  // Copy the parameters to the StagedUpdateInfo structure shared with the
  // watcher thread.
  mInfo.mGREDir = greDir;
  mInfo.mAppDir = appDir;
  mInfo.mUpdateRoot = updRoot;
  mInfo.mArgc = 0;
  mInfo.mArgv = nullptr;
  mInfo.mAppVersion = appVersion;

  MOZ_ASSERT(NS_IsMainThread(), "not main thread");
  nsCOMPtr<nsIRunnable> r =
      NewRunnableMethod("nsUpdateProcessor::StartStagedUpdate", this,
                        &nsUpdateProcessor::StartStagedUpdate);
  return NS_NewNamedThread("Update Watcher", getter_AddRefs(mProcessWatcher),
                           r);
}

NS_IMETHODIMP
nsUpdateProcessor::FixUpdateDirectoryPerms(bool aUseServiceOnFailure) {
#ifndef XP_WIN
  return NS_ERROR_NOT_IMPLEMENTED;
#else
  enum class State {
    Initializing,
    WaitingToStart,
    Starting,
    WaitingForFinish,
  };

  class FixUpdateDirectoryPermsRunnable final : public mozilla::Runnable {
   public:
    FixUpdateDirectoryPermsRunnable(const char* aName,
                                    bool aUseServiceOnFailure,
                                    const nsAutoString& aInstallPath)
        : Runnable(aName),
          mUseServiceOnFailure(aUseServiceOnFailure),
          mState(State::Initializing) {
      size_t installPathSize = aInstallPath.Length() + 1;
      mInstallPath = mozilla::MakeUnique<wchar_t[]>(installPathSize);
      if (mInstallPath) {
        HRESULT hrv = StringCchCopyW(mInstallPath.get(), installPathSize,
                                     PromiseFlatString(aInstallPath).get());
        if (FAILED(hrv)) {
          mInstallPath.reset();
        }
      }
    }

    NS_IMETHOD Run() override {
      // These constants control how often and how many times we poll the
      // maintenance service to see if it has stopped. If there is no delay in
      // the event queue, this works out to 8 minutes of polling.
      const unsigned int kMaxQueries = 2400;
      const unsigned int kQueryIntervalMS = 200;
      // These constants control how often and how many times we attempt to
      // start the service. If there is no delay in the event queue, this works
      // out to 5 seconds of polling.
      const unsigned int kMaxStartAttempts = 50;
      const unsigned int kStartAttemptIntervalMS = 100;

      if (mState == State::Initializing) {
        if (!mInstallPath) {
          LOG(
              ("Warning: No install path available in "
               "FixUpdateDirectoryPermsRunnable\n"));
        }
        // In the event that the directory is owned by this user, we may be able
        // to fix things without the maintenance service
        mozilla::UniquePtr<wchar_t[]> updateDir;
        HRESULT permResult = GetCommonUpdateDirectory(
            mInstallPath.get(), SetPermissionsOf::AllFilesAndDirs, updateDir);
        if (SUCCEEDED(permResult)) {
          LOG(("Successfully fixed permissions from within Firefox\n"));
          return NS_OK;
        } else if (!mUseServiceOnFailure) {
          LOG(
              ("Error: Unable to fix permissions within Firefox and "
               "maintenance service is disabled\n"));
          return ReportUpdateError();
        }

        SC_HANDLE serviceManager =
            OpenSCManager(nullptr, nullptr,
                          SC_MANAGER_CONNECT | SC_MANAGER_ENUMERATE_SERVICE);
        mServiceManager.own(serviceManager);
        if (!serviceManager) {
          LOG(
              ("Error: Unable to get the service manager. Cannot fix "
               "permissions.\n"));
          return NS_ERROR_FAILURE;
        }
        SC_HANDLE service = OpenServiceW(serviceManager, MAINTENANCE_SVC_NAME,
                                         SERVICE_QUERY_STATUS | SERVICE_START);
        mService.own(service);
        if (!service) {
          LOG(
              ("Error: Unable to get the maintenance service. Unable fix "
               "permissions without it.\n"));
          return NS_ERROR_FAILURE;
        }

        mStartServiceArgCount = mInstallPath ? 3 : 2;
        mStartServiceArgs =
            mozilla::MakeUnique<LPCWSTR[]>(mStartServiceArgCount);
        if (!mStartServiceArgs) {
          LOG(
              ("Error: Unable to allocate memory for argument pointers. Cannot "
               "fix permissions.\n"));
          return NS_ERROR_FAILURE;
        }
        mStartServiceArgs[0] = L"MozillaMaintenance";
        mStartServiceArgs[1] = L"fix-update-directory-perms";
        if (mInstallPath) {
          mStartServiceArgs[2] = mInstallPath.get();
        }

        mState = State::WaitingToStart;
        mCurrentTry = 1;
      }
      if (mState == State::WaitingToStart ||
          mState == State::WaitingForFinish) {
        SERVICE_STATUS_PROCESS ssp;
        DWORD bytesNeeded;
        BOOL success =
            QueryServiceStatusEx(mService, SC_STATUS_PROCESS_INFO, (LPBYTE)&ssp,
                                 sizeof(SERVICE_STATUS_PROCESS), &bytesNeeded);
        if (!success) {
          DWORD lastError = GetLastError();
          // These 3 errors can occur when the service is not yet stopped but it
          // is stopping. If we got another error, waiting will probably not
          // help.
          if (lastError != ERROR_INVALID_SERVICE_CONTROL &&
              lastError != ERROR_SERVICE_CANNOT_ACCEPT_CTRL &&
              lastError != ERROR_SERVICE_NOT_ACTIVE) {
            LOG(
                ("Error: Unable to query service when fixing permissions. Got "
                 "an error that cannot be fixed by waiting: 0x%lx\n",
                 lastError));
            return NS_ERROR_FAILURE;
          }
          if (mCurrentTry >= kMaxQueries) {
            LOG(
                ("Error: Unable to query service when fixing permissions: "
                 "Timed out after %u attempts.\n",
                 mCurrentTry));
            return NS_ERROR_FAILURE;
          }
          return RetryInMS(kQueryIntervalMS);
        } else {  // We successfully queried the service
          if (ssp.dwCurrentState != SERVICE_STOPPED) {
            return RetryInMS(kQueryIntervalMS);
          }
          if (mState == State::WaitingForFinish) {
            if (ssp.dwWin32ExitCode != NO_ERROR) {
              LOG(
                  ("Error: Maintenance Service was unable to fix update "
                   "directory permissions\n"));
              return ReportUpdateError();
            }
            LOG(
                ("Maintenance service successully fixed update directory "
                 "permissions\n"));
            return NS_OK;
          }
          mState = State::Starting;
          mCurrentTry = 1;
        }
      }
      if (mState == State::Starting) {
        BOOL success = StartServiceW(mService, mStartServiceArgCount,
                                     mStartServiceArgs.get());
        if (success) {
          mState = State::WaitingForFinish;
          mCurrentTry = 1;
          return RetryInMS(kQueryIntervalMS);
        } else if (mCurrentTry >= kMaxStartAttempts) {
          LOG(
              ("Error: Unable to fix permissions: Timed out after %u attempts "
               "to start the maintenance service\n",
               mCurrentTry));
          return NS_ERROR_FAILURE;
        }
        return RetryInMS(kStartAttemptIntervalMS);
      }
      // We should not have fallen through all three state checks above
      LOG(
          ("Error: Reached logically unreachable code when correcting update "
           "directory permissions\n"));
      return NS_ERROR_FAILURE;
    }

   private:
    bool mUseServiceOnFailure;
    unsigned int mCurrentTry;
    State mState;
    mozilla::UniquePtr<wchar_t[]> mInstallPath;
    nsAutoServiceHandle mServiceManager;
    nsAutoServiceHandle mService;
    DWORD mStartServiceArgCount;
    mozilla::UniquePtr<LPCWSTR[]> mStartServiceArgs;

    nsresult RetryInMS(unsigned int aDelayMS) {
      ++mCurrentTry;
      nsCOMPtr<nsIRunnable> runnable(this);
      return NS_DelayedDispatchToCurrentThread(runnable.forget(), aDelayMS);
    }
    nsresult ReportUpdateError() {
      return NS_DispatchToMainThread(NS_NewRunnableFunction(
          "nsUpdateProcessor::FixUpdateDirectoryPerms::"
          "FixUpdateDirectoryPermsRunnable::ReportUpdateError",
          []() -> void {
            nsCOMPtr<nsIObserverService> observerService =
                services::GetObserverService();
            if (NS_WARN_IF(!observerService)) {
              return;
            }
            observerService->NotifyObservers(nullptr, "update-error",
                                             u"bad-perms");
          }));
    }
  };

  nsCOMPtr<nsIProperties> dirSvc(
      do_GetService("@mozilla.org/file/directory_service;1"));
  NS_ENSURE_TRUE(dirSvc, NS_ERROR_FAILURE);

  nsCOMPtr<nsIFile> appPath;
  nsresult rv = dirSvc->Get(XRE_EXECUTABLE_FILE, NS_GET_IID(nsIFile),
                            getter_AddRefs(appPath));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIFile> installDir;
  rv = appPath->GetParent(getter_AddRefs(installDir));
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString installPath;
  rv = installDir->GetPath(installPath);
  NS_ENSURE_SUCCESS(rv, rv);

  // Stream transport service has a thread pool we can use so that this happens
  // off the main thread.
  nsCOMPtr<nsIEventTarget> eventTarget =
      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
  NS_ENSURE_TRUE(eventTarget, NS_ERROR_FAILURE);

  nsCOMPtr<nsIRunnable> runnable = new FixUpdateDirectoryPermsRunnable(
      "FixUpdateDirectoryPermsRunnable", aUseServiceOnFailure, installPath);
  rv = eventTarget->Dispatch(runnable.forget());
  NS_ENSURE_SUCCESS(rv, rv);
#endif
  return NS_OK;
}

void nsUpdateProcessor::StartStagedUpdate() {
  MOZ_ASSERT(!NS_IsMainThread(), "main thread");

  nsresult rv = ProcessUpdates(mInfo.mGREDir, mInfo.mAppDir, mInfo.mUpdateRoot,
                               mInfo.mArgc, mInfo.mArgv,
                               mInfo.mAppVersion.get(), false, &mUpdaterPID);
  NS_ENSURE_SUCCESS_VOID(rv);

  if (mUpdaterPID) {
    // Track the state of the updater process while it is staging an update.
    rv = NS_DispatchToCurrentThread(
        NewRunnableMethod("nsUpdateProcessor::WaitForProcess", this,
                          &nsUpdateProcessor::WaitForProcess));
    NS_ENSURE_SUCCESS_VOID(rv);
  } else {
    // Failed to launch the updater process for some reason.
    // We need to shutdown the current thread as there isn't anything more for
    // us to do...
    rv = NS_DispatchToMainThread(
        NewRunnableMethod("nsUpdateProcessor::ShutdownWatcherThread", this,
                          &nsUpdateProcessor::ShutdownWatcherThread));
    NS_ENSURE_SUCCESS_VOID(rv);
  }
}

void nsUpdateProcessor::ShutdownWatcherThread() {
  MOZ_ASSERT(NS_IsMainThread(), "not main thread");
  mProcessWatcher->Shutdown();
  mProcessWatcher = nullptr;
}

void nsUpdateProcessor::WaitForProcess() {
  MOZ_ASSERT(!NS_IsMainThread(), "main thread");
  if (ProcessHasTerminated(mUpdaterPID)) {
    NS_DispatchToMainThread(NewRunnableMethod(
        "nsUpdateProcessor::UpdateDone", this, &nsUpdateProcessor::UpdateDone));
  } else {
    NS_DispatchToCurrentThread(
        NewRunnableMethod("nsUpdateProcessor::WaitForProcess", this,
                          &nsUpdateProcessor::WaitForProcess));
  }
}

void nsUpdateProcessor::UpdateDone() {
  MOZ_ASSERT(NS_IsMainThread(), "not main thread");

  nsCOMPtr<nsIUpdateManager> um =
      do_GetService("@mozilla.org/updates/update-manager;1");
  if (um) {
    um->RefreshUpdateStatus();
  }

  ShutdownWatcherThread();
}