update/updater/updater.cpp

/* 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/. */

/**
 *  Manifest Format
 *  ---------------
 *
 *  contents = 1*( line )
 *  line     = method LWS *( param LWS ) CRLF
 *  CRLF     = "\r\n"
 *  LWS      = 1*( " " | "\t" )
 *
 *  Available methods for the manifest file:
 *
 *  updatev3.manifest
 *  -----------------
 *  method   = "add" | "add-if" | "add-if-not" | "patch" | "patch-if" |
 *             "remove" | "rmdir" | "rmrfdir" | type
 *
 *  'add-if-not' adds a file if it doesn't exist.
 *
 *  'type' is the update type (e.g. complete or partial) and when present MUST
 *  be the first entry in the update manifest. The type is used to support
 *  removing files that no longer exist when when applying a complete update by
 *  causing the actions defined in the precomplete file to be performed.
 *
 *  precomplete
 *  -----------
 *  method   = "remove" | "rmdir"
 */
#include "bspatch.h"
#include "progressui.h"
#include "archivereader.h"
#include "readstrings.h"
#include "updatererrors.h"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
#include <errno.h>
#include <algorithm>

#include "updatecommon.h"
#ifdef XP_MACOSX
#  include "updaterfileutils_osx.h"
#endif  // XP_MACOSX

#include "mozilla/Compiler.h"
#include "mozilla/Types.h"
#include "mozilla/UniquePtr.h"
#ifdef XP_WIN
#  include "mozilla/WinHeaderOnlyUtils.h"
#endif  // XP_WIN

// Amount of the progress bar to use in each of the 3 update stages,
// should total 100.0.
#define PROGRESS_PREPARE_SIZE 20.0f
#define PROGRESS_EXECUTE_SIZE 75.0f
#define PROGRESS_FINISH_SIZE 5.0f

// Maximum amount of time in ms to wait for the parent process to close. The 30
// seconds is rather long but there have been bug reports where the parent
// process has exited after 10 seconds and it is better to give it a chance.
#define PARENT_WAIT 30000

#if defined(XP_MACOSX)
// These functions are defined in launchchild_osx.mm
void CleanupElevatedMacUpdate(bool aFailureOccurred);
bool IsOwnedByGroupAdmin(const char* aAppBundle);
bool IsRecursivelyWritable(const char* aPath);
void LaunchChild(int argc, const char** argv);
void LaunchMacPostProcess(const char* aAppBundle);
bool ObtainUpdaterArguments(int* argc, char*** argv);
bool ServeElevatedUpdate(int argc, const char** argv);
void SetGroupOwnershipAndPermissions(const char* aAppBundle);
struct UpdateServerThreadArgs {
  int argc;
  const NS_tchar** argv;
};
#endif

#ifndef _O_BINARY
#  define _O_BINARY 0
#endif

#ifndef NULL
#  define NULL (0)
#endif

#ifndef SSIZE_MAX
#  define SSIZE_MAX LONG_MAX
#endif

// We want to use execv to invoke the callback executable on platforms where
// we were launched using execv.  See nsUpdateDriver.cpp.
#if defined(XP_UNIX) && !defined(XP_MACOSX)
#  define USE_EXECV
#endif

#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && !defined(XP_MACOSX)
#  include "nss.h"
#  include "prerror.h"
#endif

#include "crctable.h"

#ifdef XP_WIN
#  ifdef MOZ_MAINTENANCE_SERVICE
#    include "registrycertificates.h"
#  endif
BOOL PathAppendSafe(LPWSTR base, LPCWSTR extra);
BOOL PathGetSiblingFilePath(LPWSTR destinationBuffer, LPCWSTR siblingFilePath,
                            LPCWSTR newFileName);
#  include "updatehelper.h"

// Closes the handle if valid and if the updater is elevated returns with the
// return code specified. This prevents multiple launches of the callback
// application by preventing the elevated process from launching the callback.
#  define EXIT_WHEN_ELEVATED(path, handle, retCode) \
    {                                               \
      if (handle != INVALID_HANDLE_VALUE) {         \
        CloseHandle(handle);                        \
      }                                             \
      if (NS_tremove(path) && errno != ENOENT) {    \
        return retCode;                             \
      }                                             \
    }
#endif

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

// This BZ2_crc32Table variable lives in libbz2. We just took the
// data structure from bz2 and created crctables.h

static unsigned int crc32(const unsigned char* buf, unsigned int len) {
  unsigned int crc = 0xffffffffL;

  const unsigned char* end = buf + len;
  for (; buf != end; ++buf)
    crc = (crc << 8) ^ BZ2_crc32Table[(crc >> 24) ^ *buf];

  crc = ~crc;
  return crc;
}

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

// A simple stack based container for a FILE struct that closes the
// file descriptor from its destructor.
class AutoFile {
 public:
  explicit AutoFile(FILE* file = nullptr) : mFile(file) {}

  ~AutoFile() {
    if (mFile != nullptr) {
      fclose(mFile);
    }
  }

  AutoFile& operator=(FILE* file) {
    if (mFile != 0) {
      fclose(mFile);
    }
    mFile = file;
    return *this;
  }

  operator FILE*() { return mFile; }

  FILE* get() { return mFile; }

 private:
  FILE* mFile;
};

struct MARChannelStringTable {
  MARChannelStringTable() { MARChannelID[0] = '\0'; }

  char MARChannelID[MAX_TEXT_LEN];
};

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

#ifdef XP_MACOSX

// Just a simple class that sets a umask value in its constructor and resets
// it in its destructor.
class UmaskContext {
 public:
  explicit UmaskContext(mode_t umaskToSet);
  ~UmaskContext();

 private:
  mode_t mPreviousUmask;
};

UmaskContext::UmaskContext(mode_t umaskToSet) {
  mPreviousUmask = umask(umaskToSet);
}

UmaskContext::~UmaskContext() { umask(mPreviousUmask); }

#endif

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

typedef void (*ThreadFunc)(void* param);

#ifdef XP_WIN
#  include <process.h>

class Thread {
 public:
  int Run(ThreadFunc func, void* param) {
    mThreadFunc = func;
    mThreadParam = param;

    unsigned int threadID;

    mThread =
        (HANDLE)_beginthreadex(nullptr, 0, ThreadMain, this, 0, &threadID);

    return mThread ? 0 : -1;
  }
  int Join() {
    WaitForSingleObject(mThread, INFINITE);
    CloseHandle(mThread);
    return 0;
  }

 private:
  static unsigned __stdcall ThreadMain(void* p) {
    Thread* self = (Thread*)p;
    self->mThreadFunc(self->mThreadParam);
    return 0;
  }
  HANDLE mThread;
  ThreadFunc mThreadFunc;
  void* mThreadParam;
};

#elif defined(XP_UNIX)
#  include <pthread.h>

class Thread {
 public:
  int Run(ThreadFunc func, void* param) {
    return pthread_create(&thr, nullptr, (void* (*)(void*))func, param);
  }
  int Join() {
    void* result;
    return pthread_join(thr, &result);
  }

 private:
  pthread_t thr;
};

#else
#  error "Unsupported platform"
#endif

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

static NS_tchar gPatchDirPath[MAXPATHLEN];
static NS_tchar gInstallDirPath[MAXPATHLEN];
static NS_tchar gWorkingDirPath[MAXPATHLEN];
static ArchiveReader gArchiveReader;
static bool gSucceeded = false;
static bool sStagedUpdate = false;
static bool sReplaceRequest = false;
static bool sUsingService = false;

#ifdef XP_WIN
static NS_tchar gCallbackRelPath[MAXPATHLEN];
static NS_tchar gCallbackBackupPath[MAXPATHLEN];
static NS_tchar gDeleteDirPath[MAXPATHLEN];

// Whether to copy the update.log and update.status file to the update patch
// directory from a secure directory.
static bool gCopyOutputFiles = false;
// Whether to write the update.log and update.status file to a secure directory.
static bool gUseSecureOutputPath = false;
#endif

static const NS_tchar kWhitespace[] = NS_T(" \t");
static const NS_tchar kNL[] = NS_T("\r\n");
static const NS_tchar kQuote[] = NS_T("\"");

static inline size_t mmin(size_t a, size_t b) { return (a > b) ? b : a; }

static NS_tchar* mstrtok(const NS_tchar* delims, NS_tchar** str) {
  if (!*str || !**str) {
    *str = nullptr;
    return nullptr;
  }

  // skip leading "whitespace"
  NS_tchar* ret = *str;
  const NS_tchar* d;
  do {
    for (d = delims; *d != NS_T('\0'); ++d) {
      if (*ret == *d) {
        ++ret;
        break;
      }
    }
  } while (*d);

  if (!*ret) {
    *str = ret;
    return nullptr;
  }

  NS_tchar* i = ret;
  do {
    for (d = delims; *d != NS_T('\0'); ++d) {
      if (*i == *d) {
        *i = NS_T('\0');
        *str = ++i;
        return ret;
      }
    }
    ++i;
  } while (*i);

  *str = nullptr;
  return ret;
}

#if defined(TEST_UPDATER)
#  define HAS_ENV_CHECK 1
#elif defined(MOZ_MAINTENANCE_SERVICE)
#  define HAS_ENV_CHECK 1
#endif

#if defined(HAS_ENV_CHECK)
static bool EnvHasValue(const char* name) {
  const char* val = getenv(name);
  return (val && *val);
}
#endif

#ifdef XP_WIN
/**
 * Obtains the update ID from the secure id file located in secure output
 * directory.
 *
 * @param  outBuf
 *         A buffer of size UUID_LEN (e.g. 37) to store the result. The uuid is
 *         36 characters in length and 1 more for null termination.
 * @return true if successful
 */
bool GetSecureID(char* outBuf) {
  NS_tchar idFilePath[MAX_PATH + 1] = {L'\0'};
  if (!GetSecureOutputFilePath(gPatchDirPath, L".id", idFilePath)) {
    return false;
  }

  AutoFile idFile(NS_tfopen(idFilePath, NS_T("rb")));
  if (idFile == nullptr) {
    return false;
  }

  size_t read = fread(outBuf, UUID_LEN - 1, 1, idFile);
  if (read != 1) {
    return false;
  }

  outBuf[UUID_LEN - 1] = '\0';
  return true;
}
#endif

/**
 * Calls LogFinish for the update log. On Windows, the unelevated updater copies
 * the update status file and the update log file that were written by the
 * elevated updater from the secure directory to the update patch directory.
 *
 * NOTE: All calls to WriteStatusFile MUST happen before calling output_finish
 *       because this function copies the update status file for the elevated
 *       updater and writing the status file after calling output_finish will
 *       overwrite it.
 */
static void output_finish() {
  LogFinish();
#ifdef XP_WIN
  if (gCopyOutputFiles) {
    NS_tchar srcStatusPath[MAXPATHLEN + 1] = {NS_T('\0')};
    if (GetSecureOutputFilePath(gPatchDirPath, L".status", srcStatusPath)) {
      NS_tchar dstStatusPath[MAXPATHLEN + 1] = {NS_T('\0')};
      NS_tsnprintf(dstStatusPath,
                   sizeof(dstStatusPath) / sizeof(dstStatusPath[0]),
                   NS_T("%s\\update.status"), gPatchDirPath);
      CopyFileW(srcStatusPath, dstStatusPath, false);
    }

    NS_tchar srcLogPath[MAXPATHLEN + 1] = {NS_T('\0')};
    if (GetSecureOutputFilePath(gPatchDirPath, L".log", srcLogPath)) {
      NS_tchar dstLogPath[MAXPATHLEN + 1] = {NS_T('\0')};
      NS_tsnprintf(dstLogPath, sizeof(dstLogPath) / sizeof(dstLogPath[0]),
                   NS_T("%s\\update.log"), gPatchDirPath);
      CopyFileW(srcLogPath, dstLogPath, false);
    }
  }
#endif
}

/**
 * Coverts a relative update path to a full path.
 *
 * @param  relpath
 *         The relative path to convert to a full path.
 * @return valid filesystem full path or nullptr if memory allocation fails.
 */
static NS_tchar* get_full_path(const NS_tchar* relpath) {
  NS_tchar* destpath = sStagedUpdate ? gWorkingDirPath : gInstallDirPath;
  size_t lendestpath = NS_tstrlen(destpath);
  size_t lenrelpath = NS_tstrlen(relpath);
  NS_tchar* s = new NS_tchar[lendestpath + lenrelpath + 2];
  if (!s) {
    return nullptr;
  }

  NS_tchar* c = s;

  NS_tstrcpy(c, destpath);
  c += lendestpath;
  NS_tstrcat(c, NS_T("/"));
  c++;

  NS_tstrcat(c, relpath);
  c += lenrelpath;
  *c = NS_T('\0');
  return s;
}

/**
 * Converts a full update path into a relative path; reverses get_full_path.
 *
 * @param  fullpath
 *         The absolute path to convert into a relative path.
 * return pointer to the location within fullpath where the relative path starts
 *        or fullpath itself if it already looks relative.
 */
#ifndef XP_WIN
static const NS_tchar* get_relative_path(const NS_tchar* fullpath) {
  if (fullpath[0] != '/') {
    return fullpath;
  }

  NS_tchar* prefix = sStagedUpdate ? gWorkingDirPath : gInstallDirPath;

  // If the path isn't long enough to be absolute, return it as-is.
  if (NS_tstrlen(fullpath) <= NS_tstrlen(prefix)) {
    return fullpath;
  }

  return fullpath + NS_tstrlen(prefix) + 1;
}
#endif

/**
 * Gets the platform specific path and performs simple checks to the path. If
 * the path checks don't pass nullptr will be returned.
 *
 * @param  line
 *         The line from the manifest that contains the path.
 * @param  isdir
 *         Whether the path is a directory path. Defaults to false.
 * @return valid filesystem path or nullptr if the path checks fail.
 */
static NS_tchar* get_valid_path(NS_tchar** line, bool isdir = false) {
  NS_tchar* path = mstrtok(kQuote, line);
  if (!path) {
    LOG(("get_valid_path: unable to determine path: " LOG_S, *line));
    return nullptr;
  }

  // All paths must be relative from the current working directory
  if (path[0] == NS_T('/')) {
    LOG(("get_valid_path: path must be relative: " LOG_S, path));
    return nullptr;
  }

#ifdef XP_WIN
  // All paths must be relative from the current working directory
  if (path[0] == NS_T('\\') || path[1] == NS_T(':')) {
    LOG(("get_valid_path: path must be relative: " LOG_S, path));
    return nullptr;
  }
#endif

  if (isdir) {
    // Directory paths must have a trailing forward slash.
    if (path[NS_tstrlen(path) - 1] != NS_T('/')) {
      LOG(
          ("get_valid_path: directory paths must have a trailing forward "
           "slash: " LOG_S,
           path));
      return nullptr;
    }

    // Remove the trailing forward slash because stat on Windows will return
    // ENOENT if the path has a trailing slash.
    path[NS_tstrlen(path) - 1] = NS_T('\0');
  }

  // Don't allow relative paths that resolve to a parent directory.
  if (NS_tstrstr(path, NS_T("..")) != nullptr) {
    LOG(("get_valid_path: paths must not contain '..': " LOG_S, path));
    return nullptr;
  }

  return path;
}

/*
 * Gets a quoted path. The return value is malloc'd and it is the responsibility
 * of the caller to free it.
 *
 * @param  path
 *         The path to quote.
 * @return On success the quoted path and nullptr otherwise.
 */
static NS_tchar* get_quoted_path(const NS_tchar* path) {
  size_t lenQuote = NS_tstrlen(kQuote);
  size_t lenPath = NS_tstrlen(path);
  size_t len = lenQuote + lenPath + lenQuote + 1;

  NS_tchar* s = (NS_tchar*)malloc(len * sizeof(NS_tchar));
  if (!s) {
    return nullptr;
  }

  NS_tchar* c = s;
  NS_tstrcpy(c, kQuote);
  c += lenQuote;
  NS_tstrcat(c, path);
  c += lenPath;
  NS_tstrcat(c, kQuote);
  c += lenQuote;
  *c = NS_T('\0');
  return s;
}

static void ensure_write_permissions(const NS_tchar* path) {
#ifdef XP_WIN
  (void)_wchmod(path, _S_IREAD | _S_IWRITE);
#else
  struct stat fs;
  if (!stat(path, &fs) && !(fs.st_mode & S_IWUSR)) {
    (void)chmod(path, fs.st_mode | S_IWUSR);
  }
#endif
}

static int ensure_remove(const NS_tchar* path) {
  ensure_write_permissions(path);
  int rv = NS_tremove(path);
  if (rv) {
    LOG(("ensure_remove: failed to remove file: " LOG_S ", rv: %d, err: %d",
         path, rv, errno));
  }
  return rv;
}

// Remove the directory pointed to by path and all of its files and
// sub-directories.
static int ensure_remove_recursive(const NS_tchar* path,
                                   bool continueEnumOnFailure = false) {
  // We use lstat rather than stat here so that we can successfully remove
  // symlinks.
  struct NS_tstat_t sInfo;
  int rv = NS_tlstat(path, &sInfo);
  if (rv) {
    // This error is benign
    return rv;
  }
  if (!S_ISDIR(sInfo.st_mode)) {
    return ensure_remove(path);
  }

  NS_tDIR* dir;
  NS_tdirent* entry;

  dir = NS_topendir(path);
  if (!dir) {
    LOG(("ensure_remove_recursive: unable to open directory: " LOG_S
         ", rv: %d, err: %d",
         path, rv, errno));
    return rv;
  }

  while ((entry = NS_treaddir(dir)) != 0) {
    if (NS_tstrcmp(entry->d_name, NS_T(".")) &&
        NS_tstrcmp(entry->d_name, NS_T(".."))) {
      NS_tchar childPath[MAXPATHLEN];
      NS_tsnprintf(childPath, sizeof(childPath) / sizeof(childPath[0]),
                   NS_T("%s/%s"), path, entry->d_name);
      rv = ensure_remove_recursive(childPath);
      if (rv && !continueEnumOnFailure) {
        break;
      }
    }
  }

  NS_tclosedir(dir);

  if (rv == OK) {
    ensure_write_permissions(path);
    rv = NS_trmdir(path);
    if (rv) {
      LOG(("ensure_remove_recursive: unable to remove directory: " LOG_S
           ", rv: %d, err: %d",
           path, rv, errno));
    }
  }
  return rv;
}

static bool is_read_only(const NS_tchar* flags) {
  size_t length = NS_tstrlen(flags);
  if (length == 0) {
    return false;
  }

  // Make sure the string begins with "r"
  if (flags[0] != NS_T('r')) {
    return false;
  }

  // Look for "r+" or "r+b"
  if (length > 1 && flags[1] == NS_T('+')) {
    return false;
  }

  // Look for "rb+"
  if (NS_tstrcmp(flags, NS_T("rb+")) == 0) {
    return false;
  }

  return true;
}

static FILE* ensure_open(const NS_tchar* path, const NS_tchar* flags,
                         unsigned int options) {
  ensure_write_permissions(path);
  FILE* f = NS_tfopen(path, flags);
  if (is_read_only(flags)) {
    // Don't attempt to modify the file permissions if the file is being opened
    // in read-only mode.
    return f;
  }
  if (NS_tchmod(path, options) != 0) {
    if (f != nullptr) {
      fclose(f);
    }
    return nullptr;
  }
  struct NS_tstat_t ss;
  if (NS_tstat(path, &ss) != 0 || ss.st_mode != options) {
    if (f != nullptr) {
      fclose(f);
    }
    return nullptr;
  }
  return f;
}

// Ensure that the directory containing this file exists.
static int ensure_parent_dir(const NS_tchar* path) {
  int rv = OK;

  NS_tchar* slash = (NS_tchar*)NS_tstrrchr(path, NS_T('/'));
  if (slash) {
    *slash = NS_T('\0');
    rv = ensure_parent_dir(path);
    // Only attempt to create the directory if we're not at the root
    if (rv == OK && *path) {
      rv = NS_tmkdir(path, 0755);
      // If the directory already exists, then ignore the error.
      if (rv < 0 && errno != EEXIST) {
        LOG(("ensure_parent_dir: failed to create directory: " LOG_S ", "
             "err: %d",
             path, errno));
        rv = WRITE_ERROR;
      } else {
        rv = OK;
      }
    }
    *slash = NS_T('/');
  }
  return rv;
}

#ifdef XP_UNIX
static int ensure_copy_symlink(const NS_tchar* path, const NS_tchar* dest) {
  // Copy symlinks by creating a new symlink to the same target
  NS_tchar target[MAXPATHLEN + 1] = {NS_T('\0')};
  int rv = readlink(path, target, MAXPATHLEN);
  if (rv == -1) {
    LOG(("ensure_copy_symlink: failed to read the link: " LOG_S ", err: %d",
         path, errno));
    return READ_ERROR;
  }
  rv = symlink(target, dest);
  if (rv == -1) {
    LOG(("ensure_copy_symlink: failed to create the new link: " LOG_S
         ", target: " LOG_S " err: %d",
         dest, target, errno));
    return READ_ERROR;
  }
  return 0;
}
#endif

// Copy the file named path onto a new file named dest.
static int ensure_copy(const NS_tchar* path, const NS_tchar* dest) {
#ifdef XP_WIN
  // Fast path for Windows
  bool result = CopyFileW(path, dest, false);
  if (!result) {
    LOG(("ensure_copy: failed to copy the file " LOG_S " over to " LOG_S
         ", lasterr: %x",
         path, dest, GetLastError()));
    return WRITE_ERROR_FILE_COPY;
  }
  return OK;
#else
  struct NS_tstat_t ss;
  int rv = NS_tlstat(path, &ss);
  if (rv) {
    LOG(("ensure_copy: failed to read file status info: " LOG_S ", err: %d",
         path, errno));
    return READ_ERROR;
  }

#  ifdef XP_UNIX
  if (S_ISLNK(ss.st_mode)) {
    return ensure_copy_symlink(path, dest);
  }
#  endif

  AutoFile infile(ensure_open(path, NS_T("rb"), ss.st_mode));
  if (!infile) {
    LOG(("ensure_copy: failed to open the file for reading: " LOG_S ", err: %d",
         path, errno));
    return READ_ERROR;
  }
  AutoFile outfile(ensure_open(dest, NS_T("wb"), ss.st_mode));
  if (!outfile) {
    LOG(("ensure_copy: failed to open the file for writing: " LOG_S ", err: %d",
         dest, errno));
    return WRITE_ERROR;
  }

  // This block size was chosen pretty arbitrarily but seems like a reasonable
  // compromise. For example, the optimal block size on a modern OS X machine
  // is 100k */
  const int blockSize = 32 * 1024;
  void* buffer = malloc(blockSize);
  if (!buffer) {
    return UPDATER_MEM_ERROR;
  }

  while (!feof(infile.get())) {
    size_t read = fread(buffer, 1, blockSize, infile);
    if (ferror(infile.get())) {
      LOG(("ensure_copy: failed to read the file: " LOG_S ", err: %d", path,
           errno));
      free(buffer);
      return READ_ERROR;
    }

    size_t written = 0;

    while (written < read) {
      size_t chunkWritten = fwrite(buffer, 1, read - written, outfile);
      if (chunkWritten <= 0) {
        LOG(("ensure_copy: failed to write the file: " LOG_S ", err: %d", dest,
             errno));
        free(buffer);
        return WRITE_ERROR_FILE_COPY;
      }

      written += chunkWritten;
    }
  }

  rv = NS_tchmod(dest, ss.st_mode);

  free(buffer);
  return rv;
#endif
}

template <unsigned N>
struct copy_recursive_skiplist {
  NS_tchar paths[N][MAXPATHLEN];

  void append(unsigned index, const NS_tchar* path, const NS_tchar* suffix) {
    NS_tsnprintf(paths[index], MAXPATHLEN, NS_T("%s/%s"), path, suffix);
  }

  bool find(const NS_tchar* path) {
    for (int i = 0; i < static_cast<int>(N); ++i) {
      if (!NS_tstricmp(paths[i], path)) {
        return true;
      }
    }
    return false;
  }
};

// Copy all of the files and subdirectories under path to a new directory named
// dest. The path names in the skiplist will be skipped and will not be copied.
template <unsigned N>
static int ensure_copy_recursive(const NS_tchar* path, const NS_tchar* dest,
                                 copy_recursive_skiplist<N>& skiplist) {
  struct NS_tstat_t sInfo;
  int rv = NS_tlstat(path, &sInfo);
  if (rv) {
    LOG(("ensure_copy_recursive: path doesn't exist: " LOG_S
         ", rv: %d, err: %d",
         path, rv, errno));
    return READ_ERROR;
  }

#ifdef XP_UNIX
  if (S_ISLNK(sInfo.st_mode)) {
    return ensure_copy_symlink(path, dest);
  }
#endif

  if (!S_ISDIR(sInfo.st_mode)) {
    return ensure_copy(path, dest);
  }

  rv = NS_tmkdir(dest, sInfo.st_mode);
  if (rv < 0 && errno != EEXIST) {
    LOG(("ensure_copy_recursive: could not create destination directory: " LOG_S
         ", rv: %d, err: %d",
         path, rv, errno));
    return WRITE_ERROR;
  }

  NS_tDIR* dir;
  NS_tdirent* entry;

  dir = NS_topendir(path);
  if (!dir) {
    LOG(("ensure_copy_recursive: path is not a directory: " LOG_S
         ", rv: %d, err: %d",
         path, rv, errno));
    return READ_ERROR;
  }

  while ((entry = NS_treaddir(dir)) != 0) {
    if (NS_tstrcmp(entry->d_name, NS_T(".")) &&
        NS_tstrcmp(entry->d_name, NS_T(".."))) {
      NS_tchar childPath[MAXPATHLEN];
      NS_tsnprintf(childPath, sizeof(childPath) / sizeof(childPath[0]),
                   NS_T("%s/%s"), path, entry->d_name);
      if (skiplist.find(childPath)) {
        continue;
      }
      NS_tchar childPathDest[MAXPATHLEN];
      NS_tsnprintf(childPathDest,
                   sizeof(childPathDest) / sizeof(childPathDest[0]),
                   NS_T("%s/%s"), dest, entry->d_name);
      rv = ensure_copy_recursive(childPath, childPathDest, skiplist);
      if (rv) {
        break;
      }
    }
  }
  NS_tclosedir(dir);
  return rv;
}

// Renames the specified file to the new file specified. If the destination file
// exists it is removed.
static int rename_file(const NS_tchar* spath, const NS_tchar* dpath,
                       bool allowDirs = false) {
  int rv = ensure_parent_dir(dpath);
  if (rv) {
    return rv;
  }

  struct NS_tstat_t spathInfo;
  rv = NS_tstat(spath, &spathInfo);
  if (rv) {
    LOG(("rename_file: failed to read file status info: " LOG_S ", "
         "err: %d",
         spath, errno));
    return READ_ERROR;
  }

  if (!S_ISREG(spathInfo.st_mode)) {
    if (allowDirs && !S_ISDIR(spathInfo.st_mode)) {
      LOG(("rename_file: path present, but not a file: " LOG_S ", err: %d",
           spath, errno));
      return RENAME_ERROR_EXPECTED_FILE;
    }
    LOG(("rename_file: proceeding to rename the directory"));
  }

  if (!NS_taccess(dpath, F_OK)) {
    if (ensure_remove(dpath)) {
      LOG(
          ("rename_file: destination file exists and could not be "
           "removed: " LOG_S,
           dpath));
      return WRITE_ERROR_DELETE_FILE;
    }
  }

  if (NS_trename(spath, dpath) != 0) {
    LOG(("rename_file: failed to rename file - src: " LOG_S ", "
         "dst:" LOG_S ", err: %d",
         spath, dpath, errno));
    return WRITE_ERROR;
  }

  return OK;
}

#ifdef XP_WIN
// Remove the directory pointed to by path and all of its files and
// sub-directories. If a file is in use move it to the tobedeleted directory
// and attempt to schedule removal of the file on reboot
static int remove_recursive_on_reboot(const NS_tchar* path,
                                      const NS_tchar* deleteDir) {
  struct NS_tstat_t sInfo;
  int rv = NS_tlstat(path, &sInfo);
  if (rv) {
    // This error is benign
    return rv;
  }

  if (!S_ISDIR(sInfo.st_mode)) {
    NS_tchar tmpDeleteFile[MAXPATHLEN + 1];
    GetUUIDTempFilePath(deleteDir, L"rep", tmpDeleteFile);
    if (NS_tremove(tmpDeleteFile) && errno != ENOENT) {
      LOG(("remove_recursive_on_reboot: failed to remove temporary file: " LOG_S
           ", err: %d",
           tmpDeleteFile, errno));
    }
    rv = rename_file(path, tmpDeleteFile, false);
    if (MoveFileEx(rv ? path : tmpDeleteFile, nullptr,
                   MOVEFILE_DELAY_UNTIL_REBOOT)) {
      LOG(
          ("remove_recursive_on_reboot: file will be removed on OS "
           "reboot: " LOG_S,
           rv ? path : tmpDeleteFile));
    } else {
      LOG((
          "remove_recursive_on_reboot: failed to schedule OS reboot removal of "
          "file: " LOG_S,
          rv ? path : tmpDeleteFile));
    }
    return rv;
  }

  NS_tDIR* dir;
  NS_tdirent* entry;

  dir = NS_topendir(path);
  if (!dir) {
    LOG(("remove_recursive_on_reboot: unable to open directory: " LOG_S
         ", rv: %d, err: %d",
         path, rv, errno));
    return rv;
  }

  while ((entry = NS_treaddir(dir)) != 0) {
    if (NS_tstrcmp(entry->d_name, NS_T(".")) &&
        NS_tstrcmp(entry->d_name, NS_T(".."))) {
      NS_tchar childPath[MAXPATHLEN];
      NS_tsnprintf(childPath, sizeof(childPath) / sizeof(childPath[0]),
                   NS_T("%s/%s"), path, entry->d_name);
      // There is no need to check the return value of this call since this
      // function is only called after an update is successful and there is not
      // much that can be done to recover if it isn't successful. There is also
      // no need to log the value since it will have already been logged.
      remove_recursive_on_reboot(childPath, deleteDir);
    }
  }

  NS_tclosedir(dir);

  if (rv == OK) {
    ensure_write_permissions(path);
    rv = NS_trmdir(path);
    if (rv) {
      LOG(("remove_recursive_on_reboot: unable to remove directory: " LOG_S
           ", rv: %d, err: %d",
           path, rv, errno));
    }
  }
  return rv;
}
#endif

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

// Create a backup of the specified file by renaming it.
static int backup_create(const NS_tchar* path) {
  NS_tchar backup[MAXPATHLEN];
  NS_tsnprintf(backup, sizeof(backup) / sizeof(backup[0]),
               NS_T("%s") BACKUP_EXT, path);

  return rename_file(path, backup);
}

// Rename the backup of the specified file that was created by renaming it back
// to the original file.
static int backup_restore(const NS_tchar* path, const NS_tchar* relPath) {
  NS_tchar backup[MAXPATHLEN];
  NS_tsnprintf(backup, sizeof(backup) / sizeof(backup[0]),
               NS_T("%s") BACKUP_EXT, path);

  NS_tchar relBackup[MAXPATHLEN];
  NS_tsnprintf(relBackup, sizeof(relBackup) / sizeof(relBackup[0]),
               NS_T("%s") BACKUP_EXT, relPath);

  if (NS_taccess(backup, F_OK)) {
    LOG(("backup_restore: backup file doesn't exist: " LOG_S, relBackup));
    return OK;
  }

  return rename_file(backup, path);
}

// Discard the backup of the specified file that was created by renaming it.
static int backup_discard(const NS_tchar* path, const NS_tchar* relPath) {
  NS_tchar backup[MAXPATHLEN];
  NS_tsnprintf(backup, sizeof(backup) / sizeof(backup[0]),
               NS_T("%s") BACKUP_EXT, path);

  NS_tchar relBackup[MAXPATHLEN];
  NS_tsnprintf(relBackup, sizeof(relBackup) / sizeof(relBackup[0]),
               NS_T("%s") BACKUP_EXT, relPath);

  // Nothing to discard
  if (NS_taccess(backup, F_OK)) {
    return OK;
  }

  int rv = ensure_remove(backup);
#if defined(XP_WIN)
  if (rv && !sStagedUpdate && !sReplaceRequest) {
    LOG(("backup_discard: unable to remove: " LOG_S, relBackup));
    NS_tchar path[MAXPATHLEN + 1];
    GetUUIDTempFilePath(gDeleteDirPath, L"moz", path);
    if (rename_file(backup, path)) {
      LOG(("backup_discard: failed to rename file:" LOG_S ", dst:" LOG_S,
           relBackup, relPath));
      return WRITE_ERROR_DELETE_BACKUP;
    }
    // The MoveFileEx call to remove the file on OS reboot will fail if the
    // process doesn't have write access to the HKEY_LOCAL_MACHINE registry key
    // but this is ok since the installer / uninstaller will delete the
    // directory containing the file along with its contents after an update is
    // applied, on reinstall, and on uninstall.
    if (MoveFileEx(path, nullptr, MOVEFILE_DELAY_UNTIL_REBOOT)) {
      LOG(
          ("backup_discard: file renamed and will be removed on OS "
           "reboot: " LOG_S,
           relPath));
    } else {
      LOG(
          ("backup_discard: failed to schedule OS reboot removal of "
           "file: " LOG_S,
           relPath));
    }
  }
#else
  if (rv) {
    return WRITE_ERROR_DELETE_BACKUP;
  }
#endif

  return OK;
}

// Helper function for post-processing a temporary backup.
static void backup_finish(const NS_tchar* path, const NS_tchar* relPath,
                          int status) {
  if (status == OK) {
    backup_discard(path, relPath);
  } else {
    backup_restore(path, relPath);
  }
}

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

static int DoUpdate();

class Action {
 public:
  Action() : mProgressCost(1), mNext(nullptr) {}
  virtual ~Action() = default;

  virtual int Parse(NS_tchar* line) = 0;

  // Do any preprocessing to ensure that the action can be performed.  Execute
  // will be called if this Action and all others return OK from this method.
  virtual int Prepare() = 0;

  // Perform the operation.  Return OK to indicate success.  After all actions
  // have been executed, Finish will be called.  A requirement of Execute is
  // that its operation be reversable from Finish.
  virtual int Execute() = 0;

  // Finish is called after execution of all actions.  If status is OK, then
  // all actions were successfully executed.  Otherwise, some action failed.
  virtual void Finish(int status) = 0;

  int mProgressCost;

 private:
  Action* mNext;

  friend class ActionList;
};

class RemoveFile : public Action {
 public:
  RemoveFile() : mSkip(0) {}

  int Parse(NS_tchar* line) override;
  int Prepare() override;
  int Execute() override;
  void Finish(int status) override;

 private:
  mozilla::UniquePtr<NS_tchar[]> mFile;
  mozilla::UniquePtr<NS_tchar[]> mRelPath;
  int mSkip;
};

int RemoveFile::Parse(NS_tchar* line) {
  // format "<deadfile>"

  NS_tchar* validPath = get_valid_path(&line);
  if (!validPath) {
    return PARSE_ERROR;
  }

  mRelPath = mozilla::MakeUnique<NS_tchar[]>(MAXPATHLEN);
  NS_tstrcpy(mRelPath.get(), validPath);

  mFile.reset(get_full_path(validPath));
  if (!mFile) {
    return PARSE_ERROR;
  }

  return OK;
}

int RemoveFile::Prepare() {
  // Skip the file if it already doesn't exist.
  int rv = NS_taccess(mFile.get(), F_OK);
  if (rv) {
    mSkip = 1;
    mProgressCost = 0;
    return OK;
  }

  LOG(("PREPARE REMOVEFILE " LOG_S, mRelPath.get()));

  // Make sure that we're actually a file...
  struct NS_tstat_t fileInfo;
  rv = NS_tstat(mFile.get(), &fileInfo);
  if (rv) {
    LOG(("failed to read file status info: " LOG_S ", err: %d", mFile.get(),
         errno));
    return READ_ERROR;
  }

  if (!S_ISREG(fileInfo.st_mode)) {
    LOG(("path present, but not a file: " LOG_S, mFile.get()));
    return DELETE_ERROR_EXPECTED_FILE;
  }

  NS_tchar* slash = (NS_tchar*)NS_tstrrchr(mFile.get(), NS_T('/'));
  if (slash) {
    *slash = NS_T('\0');
    rv = NS_taccess(mFile.get(), W_OK);
    *slash = NS_T('/');
  } else {
    rv = NS_taccess(NS_T("."), W_OK);
  }

  if (rv) {
    LOG(("access failed: %d", errno));
    return WRITE_ERROR_FILE_ACCESS_DENIED;
  }

  return OK;
}

int RemoveFile::Execute() {
  if (mSkip) {
    return OK;
  }

  LOG(("EXECUTE REMOVEFILE " LOG_S, mRelPath.get()));

  // The file is checked for existence here and in Prepare since it might have
  // been removed by a separate instruction: bug 311099.
  int rv = NS_taccess(mFile.get(), F_OK);
  if (rv) {
    LOG(("file cannot be removed because it does not exist; skipping"));
    mSkip = 1;
    return OK;
  }

  if (sStagedUpdate) {
    // Staged updates don't need backup files so just remove it.
    rv = ensure_remove(mFile.get());
    if (rv) {
      return rv;
    }
  } else {
    // Rename the old file. It will be removed in Finish.
    rv = backup_create(mFile.get());
    if (rv) {
      LOG(("backup_create failed: %d", rv));
      return rv;
    }
  }

  return OK;
}

void RemoveFile::Finish(int status) {
  if (mSkip) {
    return;
  }

  LOG(("FINISH REMOVEFILE " LOG_S, mRelPath.get()));

  // Staged updates don't create backup files.
  if (!sStagedUpdate) {
    backup_finish(mFile.get(), mRelPath.get(), status);
  }
}

class RemoveDir : public Action {
 public:
  RemoveDir() : mSkip(0) {}

  int Parse(NS_tchar* line) override;
  int Prepare() override;  // check that the source dir exists
  int Execute() override;
  void Finish(int status) override;

 private:
  mozilla::UniquePtr<NS_tchar[]> mDir;
  mozilla::UniquePtr<NS_tchar[]> mRelPath;
  int mSkip;
};

int RemoveDir::Parse(NS_tchar* line) {
  // format "<deaddir>/"

  NS_tchar* validPath = get_valid_path(&line, true);
  if (!validPath) {
    return PARSE_ERROR;
  }

  mRelPath = mozilla::MakeUnique<NS_tchar[]>(MAXPATHLEN);
  NS_tstrcpy(mRelPath.get(), validPath);

  mDir.reset(get_full_path(validPath));
  if (!mDir) {
    return PARSE_ERROR;
  }

  return OK;
}

int RemoveDir::Prepare() {
  // We expect the directory to exist if we are to remove it.
  int rv = NS_taccess(mDir.get(), F_OK);
  if (rv) {
    mSkip = 1;
    mProgressCost = 0;
    return OK;
  }

  LOG(("PREPARE REMOVEDIR " LOG_S "/", mRelPath.get()));

  // Make sure that we're actually a dir.
  struct NS_tstat_t dirInfo;
  rv = NS_tstat(mDir.get(), &dirInfo);
  if (rv) {
    LOG(("failed to read directory status info: " LOG_S ", err: %d",
         mRelPath.get(), errno));
    return READ_ERROR;
  }

  if (!S_ISDIR(dirInfo.st_mode)) {
    LOG(("path present, but not a directory: " LOG_S, mRelPath.get()));
    return DELETE_ERROR_EXPECTED_DIR;
  }

  rv = NS_taccess(mDir.get(), W_OK);
  if (rv) {
    LOG(("access failed: %d, %d", rv, errno));
    return WRITE_ERROR_DIR_ACCESS_DENIED;
  }

  return OK;
}

int RemoveDir::Execute() {
  if (mSkip) {
    return OK;
  }

  LOG(("EXECUTE REMOVEDIR " LOG_S "/", mRelPath.get()));

  // The directory is checked for existence at every step since it might have
  // been removed by a separate instruction: bug 311099.
  int rv = NS_taccess(mDir.get(), F_OK);
  if (rv) {
    LOG(("directory no longer exists; skipping"));
    mSkip = 1;
  }

  return OK;
}

void RemoveDir::Finish(int status) {
  if (mSkip || status != OK) {
    return;
  }

  LOG(("FINISH REMOVEDIR " LOG_S "/", mRelPath.get()));

  // The directory is checked for existence at every step since it might have
  // been removed by a separate instruction: bug 311099.
  int rv = NS_taccess(mDir.get(), F_OK);
  if (rv) {
    LOG(("directory no longer exists; skipping"));
    return;
  }

  if (status == OK) {
    if (NS_trmdir(mDir.get())) {
      LOG(("non-fatal error removing directory: " LOG_S "/, rv: %d, err: %d",
           mRelPath.get(), rv, errno));
    }
  }
}

class AddFile : public Action {
 public:
  AddFile() : mAdded(false) {}

  int Parse(NS_tchar* line) override;
  int Prepare() override;
  int Execute() override;
  void Finish(int status) override;

 private:
  mozilla::UniquePtr<NS_tchar[]> mFile;
  mozilla::UniquePtr<NS_tchar[]> mRelPath;
  bool mAdded;
};

int AddFile::Parse(NS_tchar* line) {
  // format "<newfile>"

  NS_tchar* validPath = get_valid_path(&line);
  if (!validPath) {
    return PARSE_ERROR;
  }

  mRelPath = mozilla::MakeUnique<NS_tchar[]>(MAXPATHLEN);
  NS_tstrcpy(mRelPath.get(), validPath);

  mFile.reset(get_full_path(validPath));
  if (!mFile) {
    return PARSE_ERROR;
  }

  return OK;
}

int AddFile::Prepare() {
  LOG(("PREPARE ADD " LOG_S, mRelPath.get()));

  return OK;
}

int AddFile::Execute() {
  LOG(("EXECUTE ADD " LOG_S, mRelPath.get()));

  int rv;

  // First make sure that we can actually get rid of any existing file.
  rv = NS_taccess(mFile.get(), F_OK);
  if (rv == 0) {
    if (sStagedUpdate) {
      // Staged updates don't need backup files so just remove it.
      rv = ensure_remove(mFile.get());
    } else {
      rv = backup_create(mFile.get());
    }
    if (rv) {
      return rv;
    }
  } else {
    rv = ensure_parent_dir(mFile.get());
    if (rv) {
      return rv;
    }
  }

#ifdef XP_WIN
  char sourcefile[MAXPATHLEN];
  if (!WideCharToMultiByte(CP_UTF8, 0, mRelPath.get(), -1, sourcefile,
                           MAXPATHLEN, nullptr, nullptr)) {
    LOG(("error converting wchar to utf8: %d", GetLastError()));
    return STRING_CONVERSION_ERROR;
  }

  rv = gArchiveReader.ExtractFile(sourcefile, mFile.get());
#else
  rv = gArchiveReader.ExtractFile(mRelPath.get(), mFile.get());
#endif
  if (!rv) {
    mAdded = true;
  }
  return rv;
}

void AddFile::Finish(int status) {
  LOG(("FINISH ADD " LOG_S, mRelPath.get()));
  // Staged updates don't create backup files.
  if (!sStagedUpdate) {
    // When there is an update failure and a file has been added it is removed
    // here since there might not be a backup to replace it.
    if (status && mAdded) {
      if (NS_tremove(mFile.get()) && errno != ENOENT) {
        LOG(("non-fatal error after update failure removing added file: " LOG_S
             ", err: %d",
             mFile.get(), errno));
      }
    }
    backup_finish(mFile.get(), mRelPath.get(), status);
  }
}

class PatchFile : public Action {
 public:
  PatchFile() : mPatchFile(nullptr), mPatchIndex(-1), buf(nullptr) {}

  ~PatchFile() override;

  int Parse(NS_tchar* line) override;
  int Prepare() override;  // should check for patch file and for checksum here
  int Execute() override;
  void Finish(int status) override;

 private:
  int LoadSourceFile(FILE* ofile);

  static int sPatchIndex;

  const NS_tchar* mPatchFile;
  mozilla::UniquePtr<NS_tchar[]> mFile;
  mozilla::UniquePtr<NS_tchar[]> mFileRelPath;
  int mPatchIndex;
  MBSPatchHeader header;
  unsigned char* buf;
  NS_tchar spath[MAXPATHLEN];
  AutoFile mPatchStream;
};

int PatchFile::sPatchIndex = 0;

PatchFile::~PatchFile() {
  // Make sure mPatchStream gets unlocked on Windows; the system will do that,
  // but not until some indeterminate future time, and we want determinism.
  // Normally this happens at the end of Execute, when we close the stream;
  // this call is here in case Execute errors out.
#ifdef XP_WIN
  if (mPatchStream) {
    UnlockFile((HANDLE)_get_osfhandle(fileno(mPatchStream)), 0, 0, -1, -1);
  }
#endif
  // Patch files are written to the <working_dir>/updating directory which is
  // removed after the update has finished so don't delete patch files here.

  if (buf) {
    free(buf);
  }
}

int PatchFile::LoadSourceFile(FILE* ofile) {
  struct stat os;
  int rv = fstat(fileno((FILE*)ofile), &os);
  if (rv) {
    LOG(("LoadSourceFile: unable to stat destination file: " LOG_S ", "
         "err: %d",
         mFileRelPath.get(), errno));
    return READ_ERROR;
  }

  if (uint32_t(os.st_size) != header.slen) {
    LOG(
        ("LoadSourceFile: destination file size %d does not match expected "
         "size %d",
         uint32_t(os.st_size), header.slen));
    return LOADSOURCE_ERROR_WRONG_SIZE;
  }

  buf = (unsigned char*)malloc(header.slen);
  if (!buf) {
    return UPDATER_MEM_ERROR;
  }

  size_t r = header.slen;
  unsigned char* rb = buf;
  while (r) {
    const size_t count = mmin(SSIZE_MAX, r);
    size_t c = fread(rb, 1, count, ofile);
    if (c != count) {
      LOG(("LoadSourceFile: error reading destination file: " LOG_S,
           mFileRelPath.get()));
      return READ_ERROR;
    }

    r -= c;
    rb += c;
  }

  // Verify that the contents of the source file correspond to what we expect.

  unsigned int crc = crc32(buf, header.slen);

  if (crc != header.scrc32) {
    LOG(
        ("LoadSourceFile: destination file crc %d does not match expected "
         "crc %d",
         crc, header.scrc32));
    return CRC_ERROR;
  }

  return OK;
}

int PatchFile::Parse(NS_tchar* line) {
  // format "<patchfile>" "<filetopatch>"

  // Get the path to the patch file inside of the mar
  mPatchFile = mstrtok(kQuote, &line);
  if (!mPatchFile) {
    return PARSE_ERROR;
  }

  // consume whitespace between args
  NS_tchar* q = mstrtok(kQuote, &line);
  if (!q) {
    return PARSE_ERROR;
  }

  NS_tchar* validPath = get_valid_path(&line);
  if (!validPath) {
    return PARSE_ERROR;
  }

  mFileRelPath = mozilla::MakeUnique<NS_tchar[]>(MAXPATHLEN);
  NS_tstrcpy(mFileRelPath.get(), validPath);

  mFile.reset(get_full_path(validPath));
  if (!mFile) {
    return PARSE_ERROR;
  }

  return OK;
}

int PatchFile::Prepare() {
  LOG(("PREPARE PATCH " LOG_S, mFileRelPath.get()));

  // extract the patch to a temporary file
  mPatchIndex = sPatchIndex++;

  NS_tsnprintf(spath, sizeof(spath) / sizeof(spath[0]),
               NS_T("%s/updating/%d.patch"), gWorkingDirPath, mPatchIndex);

  // The removal of pre-existing patch files here is in case a previous update
  // crashed and left these files behind.
  if (NS_tremove(spath) && errno != ENOENT) {
    LOG(("failure removing pre-existing patch file: " LOG_S ", err: %d", spath,
         errno));
    return WRITE_ERROR;
  }

  mPatchStream = NS_tfopen(spath, NS_T("wb+"));
  if (!mPatchStream) {
    return WRITE_ERROR;
  }

#ifdef XP_WIN
  // Lock the patch file, so it can't be messed with between
  // when we're done creating it and when we go to apply it.
  if (!LockFile((HANDLE)_get_osfhandle(fileno(mPatchStream)), 0, 0, -1, -1)) {
    LOG(("Couldn't lock patch file: %d", GetLastError()));
    return LOCK_ERROR_PATCH_FILE;
  }

  char sourcefile[MAXPATHLEN];
  if (!WideCharToMultiByte(CP_UTF8, 0, mPatchFile, -1, sourcefile, MAXPATHLEN,
                           nullptr, nullptr)) {
    LOG(("error converting wchar to utf8: %d", GetLastError()));
    return STRING_CONVERSION_ERROR;
  }

  int rv = gArchiveReader.ExtractFileToStream(sourcefile, mPatchStream);
#else
  int rv = gArchiveReader.ExtractFileToStream(mPatchFile, mPatchStream);
#endif

  return rv;
}

int PatchFile::Execute() {
  LOG(("EXECUTE PATCH " LOG_S, mFileRelPath.get()));

  fseek(mPatchStream, 0, SEEK_SET);

  int rv = MBS_ReadHeader(mPatchStream, &header);
  if (rv) {
    return rv;
  }

  FILE* origfile = nullptr;
#ifdef XP_WIN
  if (NS_tstrcmp(mFileRelPath.get(), gCallbackRelPath) == 0) {
    // Read from the copy of the callback when patching since the callback can't
    // be opened for reading to prevent the application from being launched.
    origfile = NS_tfopen(gCallbackBackupPath, NS_T("rb"));
  } else {
    origfile = NS_tfopen(mFile.get(), NS_T("rb"));
  }
#else
  origfile = NS_tfopen(mFile.get(), NS_T("rb"));
#endif

  if (!origfile) {
    LOG(("unable to open destination file: " LOG_S ", err: %d",
         mFileRelPath.get(), errno));
    return READ_ERROR;
  }

  rv = LoadSourceFile(origfile);
  fclose(origfile);
  if (rv) {
    LOG(("LoadSourceFile failed"));
    return rv;
  }

  // Rename the destination file if it exists before proceeding so it can be
  // used to restore the file to its original state if there is an error.
  struct NS_tstat_t ss;
  rv = NS_tstat(mFile.get(), &ss);
  if (rv) {
    LOG(("failed to read file status info: " LOG_S ", err: %d",
         mFileRelPath.get(), errno));
    return READ_ERROR;
  }

  // Staged updates don't need backup files.
  if (!sStagedUpdate) {
    rv = backup_create(mFile.get());
    if (rv) {
      return rv;
    }
  }

#if defined(HAVE_POSIX_FALLOCATE)
  AutoFile ofile(ensure_open(mFile.get(), NS_T("wb+"), ss.st_mode));
  posix_fallocate(fileno((FILE*)ofile), 0, header.dlen);
#elif defined(XP_WIN)
  bool shouldTruncate = true;
  // Creating the file, setting the size, and then closing the file handle
  // lessens fragmentation more than any other method tested. Other methods that
  // have been tested are:
  // 1. _chsize / _chsize_s reduced fragmentation though not completely.
  // 2. _get_osfhandle and then setting the size reduced fragmentation though
  //    not completely. There are also reports of _get_osfhandle failing on
  //    mingw.
  HANDLE hfile = CreateFileW(mFile.get(), GENERIC_WRITE, 0, nullptr,
                             CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr);

  if (hfile != INVALID_HANDLE_VALUE) {
    if (SetFilePointer(hfile, header.dlen, nullptr, FILE_BEGIN) !=
            INVALID_SET_FILE_POINTER &&
        SetEndOfFile(hfile) != 0) {
      shouldTruncate = false;
    }
    CloseHandle(hfile);
  }

  AutoFile ofile(ensure_open(
      mFile.get(), shouldTruncate ? NS_T("wb+") : NS_T("rb+"), ss.st_mode));
#elif defined(XP_MACOSX)
  AutoFile ofile(ensure_open(mFile.get(), NS_T("wb+"), ss.st_mode));
  // Modified code from FileUtils.cpp
  fstore_t store = {F_ALLOCATECONTIG, F_PEOFPOSMODE, 0, header.dlen};
  // Try to get a continous chunk of disk space
  rv = fcntl(fileno((FILE*)ofile), F_PREALLOCATE, &store);
  if (rv == -1) {
    // OK, perhaps we are too fragmented, allocate non-continuous
    store.fst_flags = F_ALLOCATEALL;
    rv = fcntl(fileno((FILE*)ofile), F_PREALLOCATE, &store);
  }

  if (rv != -1) {
    ftruncate(fileno((FILE*)ofile), header.dlen);
  }
#else
  AutoFile ofile(ensure_open(mFile.get(), NS_T("wb+"), ss.st_mode));
#endif

  if (ofile == nullptr) {
    LOG(("unable to create new file: " LOG_S ", err: %d", mFileRelPath.get(),
         errno));
    return WRITE_ERROR_OPEN_PATCH_FILE;
  }

#ifdef XP_WIN
  if (!shouldTruncate) {
    fseek(ofile, 0, SEEK_SET);
  }
#endif

  rv = MBS_ApplyPatch(&header, mPatchStream, buf, ofile);

  // Go ahead and do a bit of cleanup now to minimize runtime overhead.
  // Make sure mPatchStream gets unlocked on Windows; the system will do that,
  // but not until some indeterminate future time, and we want determinism.
#ifdef XP_WIN
  UnlockFile((HANDLE)_get_osfhandle(fileno(mPatchStream)), 0, 0, -1, -1);
#endif
  // Set mPatchStream to nullptr to make AutoFile close the file,
  // so it can be deleted on Windows.
  mPatchStream = nullptr;
  // Patch files are written to the <working_dir>/updating directory which is
  // removed after the update has finished so don't delete patch files here.
  spath[0] = NS_T('\0');
  free(buf);
  buf = nullptr;

  return rv;
}

void PatchFile::Finish(int status) {
  LOG(("FINISH PATCH " LOG_S, mFileRelPath.get()));

  // Staged updates don't create backup files.
  if (!sStagedUpdate) {
    backup_finish(mFile.get(), mFileRelPath.get(), status);
  }
}

class AddIfFile : public AddFile {
 public:
  int Parse(NS_tchar* line) override;
  int Prepare() override;
  int Execute() override;
  void Finish(int status) override;

 protected:
  mozilla::UniquePtr<NS_tchar[]> mTestFile;
};

int AddIfFile::Parse(NS_tchar* line) {
  // format "<testfile>" "<newfile>"

  mTestFile.reset(get_full_path(get_valid_path(&line)));
  if (!mTestFile) {
    return PARSE_ERROR;
  }

  // consume whitespace between args
  NS_tchar* q = mstrtok(kQuote, &line);
  if (!q) {
    return PARSE_ERROR;
  }

  return AddFile::Parse(line);
}

int AddIfFile::Prepare() {
  // If the test file does not exist, then skip this action.
  if (NS_taccess(mTestFile.get(), F_OK)) {
    mTestFile = nullptr;
    return OK;
  }

  return AddFile::Prepare();
}

int AddIfFile::Execute() {
  if (!mTestFile) {
    return OK;
  }

  return AddFile::Execute();
}

void AddIfFile::Finish(int status) {
  if (!mTestFile) {
    return;
  }

  AddFile::Finish(status);
}

class AddIfNotFile : public AddFile {
 public:
  int Parse(NS_tchar* line) override;
  int Prepare() override;
  int Execute() override;
  void Finish(int status) override;

 protected:
  mozilla::UniquePtr<NS_tchar[]> mTestFile;
};

int AddIfNotFile::Parse(NS_tchar* line) {
  // format "<testfile>" "<newfile>"

  mTestFile.reset(get_full_path(get_valid_path(&line)));
  if (!mTestFile) {
    return PARSE_ERROR;
  }

  // consume whitespace between args
  NS_tchar* q = mstrtok(kQuote, &line);
  if (!q) {
    return PARSE_ERROR;
  }

  return AddFile::Parse(line);
}

int AddIfNotFile::Prepare() {
  // If the test file exists, then skip this action.
  if (!NS_taccess(mTestFile.get(), F_OK)) {
    mTestFile = NULL;
    return OK;
  }

  return AddFile::Prepare();
}

int AddIfNotFile::Execute() {
  if (!mTestFile) {
    return OK;
  }

  return AddFile::Execute();
}

void AddIfNotFile::Finish(int status) {
  if (!mTestFile) {
    return;
  }

  AddFile::Finish(status);
}

class PatchIfFile : public PatchFile {
 public:
  int Parse(NS_tchar* line) override;
  int Prepare() override;  // should check for patch file and for checksum here
  int Execute() override;
  void Finish(int status) override;

 private:
  mozilla::UniquePtr<NS_tchar[]> mTestFile;
};

int PatchIfFile::Parse(NS_tchar* line) {
  // format "<testfile>" "<patchfile>" "<filetopatch>"

  mTestFile.reset(get_full_path(get_valid_path(&line)));
  if (!mTestFile) {
    return PARSE_ERROR;
  }

  // consume whitespace between args
  NS_tchar* q = mstrtok(kQuote, &line);
  if (!q) {
    return PARSE_ERROR;
  }

  return PatchFile::Parse(line);
}

int PatchIfFile::Prepare() {
  // If the test file does not exist, then skip this action.
  if (NS_taccess(mTestFile.get(), F_OK)) {
    mTestFile = nullptr;
    return OK;
  }

  return PatchFile::Prepare();
}

int PatchIfFile::Execute() {
  if (!mTestFile) {
    return OK;
  }

  return PatchFile::Execute();
}

void PatchIfFile::Finish(int status) {
  if (!mTestFile) {
    return;
  }

  PatchFile::Finish(status);
}

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

#ifdef XP_WIN
#  include "nsWindowsRestart.cpp"
#  include "nsWindowsHelpers.h"
#  include "uachelper.h"
#  ifdef MOZ_MAINTENANCE_SERVICE
#    include "pathhash.h"
#  endif

/**
 * Launch the post update application (helper.exe). It takes in the path of the
 * callback application to calculate the path of helper.exe. For service updates
 * this is called from both the system account and the current user account.
 *
 * @param  installationDir The path to the callback application binary.
 * @param  updateInfoDir   The directory where update info is stored.
 * @return true if there was no error starting the process.
 */
bool LaunchWinPostProcess(const WCHAR* installationDir,
                          const WCHAR* updateInfoDir) {
  WCHAR workingDirectory[MAX_PATH + 1] = {L'\0'};
  wcsncpy(workingDirectory, installationDir, MAX_PATH);

  // Launch helper.exe to perform post processing (e.g. registry and log file
  // modifications) for the update.
  WCHAR inifile[MAX_PATH + 1] = {L'\0'};
  wcsncpy(inifile, installationDir, MAX_PATH);
  if (!PathAppendSafe(inifile, L"updater.ini")) {
    return false;
  }

  WCHAR exefile[MAX_PATH + 1];
  WCHAR exearg[MAX_PATH + 1];
  WCHAR exeasync[10];
  bool async = true;
  if (!GetPrivateProfileStringW(L"PostUpdateWin", L"ExeRelPath", nullptr,
                                exefile, MAX_PATH + 1, inifile)) {
    return false;
  }

  if (!GetPrivateProfileStringW(L"PostUpdateWin", L"ExeArg", nullptr, exearg,
                                MAX_PATH + 1, inifile)) {
    return false;
  }

  if (!GetPrivateProfileStringW(
          L"PostUpdateWin", L"ExeAsync", L"TRUE", exeasync,
          sizeof(exeasync) / sizeof(exeasync[0]), inifile)) {
    return false;
  }

  // The relative path must not contain directory traversals, current directory,
  // or colons.
  if (wcsstr(exefile, L"..") != nullptr || wcsstr(exefile, L"./") != nullptr ||
      wcsstr(exefile, L".\\") != nullptr || wcsstr(exefile, L":") != nullptr) {
    return false;
  }

  // The relative path must not start with a decimal point, backslash, or
  // forward slash.
  if (exefile[0] == L'.' || exefile[0] == L'\\' || exefile[0] == L'/') {
    return false;
  }

  WCHAR exefullpath[MAX_PATH + 1] = {L'\0'};
  wcsncpy(exefullpath, installationDir, MAX_PATH);
  if (!PathAppendSafe(exefullpath, exefile)) {
    return false;
  }

  if (!IsValidFullPath(exefullpath)) {
    return false;
  }

#  if !defined(TEST_UPDATER) && defined(MOZ_MAINTENANCE_SERVICE)
  if (sUsingService &&
      !DoesBinaryMatchAllowedCertificates(installationDir, exefullpath)) {
    return false;
  }
#  endif

  WCHAR dlogFile[MAX_PATH + 1];
  if (!PathGetSiblingFilePath(dlogFile, exefullpath, L"uninstall.update")) {
    return false;
  }

  WCHAR slogFile[MAX_PATH + 1] = {L'\0'};
  if (gCopyOutputFiles) {
    if (!GetSecureOutputFilePath(gPatchDirPath, L".log", slogFile)) {
      return false;
    }
  } else {
    wcsncpy(slogFile, updateInfoDir, MAX_PATH);
    if (!PathAppendSafe(slogFile, L"update.log")) {
      return false;
    }
  }

  WCHAR dummyArg[14] = {L'\0'};
  wcsncpy(dummyArg, L"argv0ignored ",
          sizeof(dummyArg) / sizeof(dummyArg[0]) - 1);

  size_t len = wcslen(exearg) + wcslen(dummyArg);
  WCHAR* cmdline = (WCHAR*)malloc((len + 1) * sizeof(WCHAR));
  if (!cmdline) {
    return false;
  }

  wcsncpy(cmdline, dummyArg, len);
  wcscat(cmdline, exearg);

  if (sUsingService || !_wcsnicmp(exeasync, L"false", 6) ||
      !_wcsnicmp(exeasync, L"0", 2)) {
    async = false;
  }

  // We want to launch the post update helper app to update the Windows
  // registry even if there is a failure with removing the uninstall.update
  // file or copying the update.log file.
  CopyFileW(slogFile, dlogFile, false);

  STARTUPINFOW si = {sizeof(si), 0};
  si.lpDesktop = const_cast<LPWSTR>(L"");  // -Wwritable-strings
  PROCESS_INFORMATION pi = {0};

  bool ok = CreateProcessW(exefullpath, cmdline,
                           nullptr,  // no special security attributes
                           nullptr,  // no special thread attributes
                           false,    // don't inherit filehandles
                           0,        // No special process creation flags
                           nullptr,  // inherit my environment
                           workingDirectory, &si, &pi);
  free(cmdline);
  if (ok) {
    if (!async) {
      WaitForSingleObject(pi.hProcess, INFINITE);
    }
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
  }
  return ok;
}

#endif

static void LaunchCallbackApp(const NS_tchar* workingDir, int argc,
                              NS_tchar** argv, bool usingService) {
  putenv(const_cast<char*>("MOZ_LAUNCHED_CHILD=1"));

  // Run from the specified working directory (see bug 312360).
  if (NS_tchdir(workingDir) != 0) {
    LOG(("Warning: chdir failed"));
  }

#if defined(USE_EXECV)
  execv(argv[0], argv);
#elif defined(XP_MACOSX)
  LaunchChild(argc, (const char**)argv);
#elif defined(XP_WIN)
  // Do not allow the callback to run when running an update through the
  // service as session 0.  The unelevated updater.exe will do the launching.
  if (!usingService) {
    HANDLE hProcess;
    if (WinLaunchChild(argv[0], argc, argv, nullptr, &hProcess)) {
      // Keep the current process around until the callback process has created
      // its message queue, to avoid the launched process's windows being forced
      // into the background.
      mozilla::WaitForInputIdle(hProcess);
      CloseHandle(hProcess);
    }
  }
#else
#  warning "Need implementaton of LaunchCallbackApp"
#endif
}

static bool WriteToFile(const NS_tchar* aFilename, const char* aStatus) {
  NS_tchar statusFilePath[MAXPATHLEN + 1] = {NS_T('\0')};
#if defined(XP_WIN)
  if (gUseSecureOutputPath) {
    if (!GetSecureOutputFilePath(gPatchDirPath, L".status", statusFilePath)) {
      return false;
    }
  } else {
    NS_tsnprintf(statusFilePath,
                 sizeof(statusFilePath) / sizeof(statusFilePath[0]),
                 NS_T("%s\\%s"), gPatchDirPath, aFilename);
  }
#else
  NS_tsnprintf(statusFilePath,
               sizeof(statusFilePath) / sizeof(statusFilePath[0]),
               NS_T("%s/%s"), gPatchDirPath, aFilename);
  // Make sure that the directory for the update status file exists
  if (ensure_parent_dir(statusFilePath)) {
    return false;
  }
#endif

  AutoFile statusFile(NS_tfopen(statusFilePath, NS_T("wb+")));
  if (statusFile == nullptr) {
    return false;
  }

  if (fwrite(aStatus, strlen(aStatus), 1, statusFile) != 1) {
    return false;
  }

#if defined(XP_WIN)
  if (gUseSecureOutputPath) {
    // This is done after the update status file has been written so if the
    // write to the update status file fails an existing update status file
    // won't be used.
    if (!WriteSecureIDFile(gPatchDirPath)) {
      return false;
    }
  }
#endif

  return true;
}

/**
 * Writes a string to the update.status file.
 *
 * NOTE: All calls to WriteStatusFile MUST happen before calling output_finish
 *       because the output_finish function copies the update status file for
 *       the elevated updater and writing the status file after calling
 *       output_finish will overwrite it.
 *
 * @param  aStatus
 *         The string to write to the update.status file.
 * @return true on success.
 */
static bool WriteStatusFile(const char* aStatus) {
  return WriteToFile(NS_T("update.status"), aStatus);
}

/**
 * Writes a string to the update.status file based on the status param.
 *
 * NOTE: All calls to WriteStatusFile MUST happen before calling output_finish
 *       because the output_finish function copies the update status file for
 *       the elevated updater and writing the status file after calling
 *       output_finish will overwrite it.
 *
 * @param  status
 *         A status code used to determine what string to write to the
 *         update.status file (see code).
 */
static void WriteStatusFile(int status) {
  const char* text;

  char buf[32];
  if (status == OK) {
    if (sStagedUpdate) {
      text = "applied\n";
    } else {
      text = "succeeded\n";
    }
  } else {
    snprintf(buf, sizeof(buf) / sizeof(buf[0]), "failed: %d\n", status);
    text = buf;
  }

  WriteStatusFile(text);
}

#ifdef MOZ_MAINTENANCE_SERVICE
/*
 * Read the update.status file and sets isPendingService to true if
 * the status is set to pending-service.
 *
 * @param  isPendingService Out parameter for specifying if the status
 *         is set to pending-service or not.
 * @return true if the information was retrieved and it is pending
 *         or pending-service.
 */
static bool IsUpdateStatusPendingService() {
  NS_tchar filename[MAXPATHLEN];
  NS_tsnprintf(filename, sizeof(filename) / sizeof(filename[0]),
               NS_T("%s/update.status"), gPatchDirPath);

  AutoFile file(NS_tfopen(filename, NS_T("rb")));
  if (file == nullptr) {
    return false;
  }

  char buf[32] = {0};
  fread(buf, sizeof(buf), 1, file);

  const char kPendingService[] = "pending-service";
  const char kAppliedService[] = "applied-service";

  return (strncmp(buf, kPendingService, sizeof(kPendingService) - 1) == 0) ||
         (strncmp(buf, kAppliedService, sizeof(kAppliedService) - 1) == 0);
}
#endif

#if defined(XP_WIN) && defined(MOZ_MAINTENANCE_SERVICE)
/*
 * Reads the secure update status file and sets isSucceeded to true if the
 * status is set to succeeded.
 *
 * @param  isSucceeded Out parameter for specifying if the status
 *         is set to succeeded or not.
 * @return true if the information was retrieved and it is succeeded.
 */
static bool IsSecureUpdateStatusSucceeded(bool& isSucceeded) {
  isSucceeded = false;
  NS_tchar statusFilePath[MAX_PATH + 1] = {L'\0'};
  if (!GetSecureOutputFilePath(gPatchDirPath, L".status", statusFilePath)) {
    return FALSE;
  }

  AutoFile file(NS_tfopen(statusFilePath, NS_T("rb")));
  if (file == nullptr) {
    return false;
  }

  char buf[32] = {0};
  fread(buf, sizeof(buf), 1, file);

  const char kSucceeded[] = "succeeded";
  isSucceeded = strncmp(buf, kSucceeded, sizeof(kSucceeded) - 1) == 0;
  return true;
}
#endif

/*
 * Copy the entire contents of the application installation directory to the
 * destination directory for the update process.
 *
 * @return 0 if successful, an error code otherwise.
 */
static int CopyInstallDirToDestDir() {
  // These files should not be copied over to the updated app
#ifdef XP_WIN
#  define SKIPLIST_COUNT 3
#elif XP_MACOSX
#  define SKIPLIST_COUNT 0
#else
#  define SKIPLIST_COUNT 2
#endif
  copy_recursive_skiplist<SKIPLIST_COUNT> skiplist;
#ifndef XP_MACOSX
  skiplist.append(0, gInstallDirPath, NS_T("updated"));
  skiplist.append(1, gInstallDirPath, NS_T("updates/0"));
#  ifdef XP_WIN
  skiplist.append(2, gInstallDirPath, NS_T("updated.update_in_progress.lock"));
#  endif
#endif

  return ensure_copy_recursive(gInstallDirPath, gWorkingDirPath, skiplist);
}

/*
 * Replace the application installation directory with the destination
 * directory in order to finish a staged update task
 *
 * @return 0 if successful, an error code otherwise.
 */
static int ProcessReplaceRequest() {
  // The replacement algorithm is like this:
  // 1. Move destDir to tmpDir.  In case of failure, abort.
  // 2. Move newDir to destDir.  In case of failure, revert step 1 and abort.
  // 3. Delete tmpDir (or defer it to the next reboot).

#ifdef XP_MACOSX
  NS_tchar destDir[MAXPATHLEN];
  NS_tsnprintf(destDir, sizeof(destDir) / sizeof(destDir[0]),
               NS_T("%s/Contents"), gInstallDirPath);
#elif XP_WIN
  // Windows preserves the case of the file/directory names.  We use the
  // GetLongPathName API in order to get the correct case for the directory
  // name, so that if the user has used a different case when launching the
  // application, the installation directory's name does not change.
  NS_tchar destDir[MAXPATHLEN];
  if (!GetLongPathNameW(gInstallDirPath, destDir,
                        sizeof(destDir) / sizeof(destDir[0]))) {
    return NO_INSTALLDIR_ERROR;
  }
#else
  NS_tchar* destDir = gInstallDirPath;
#endif

  NS_tchar tmpDir[MAXPATHLEN];
  NS_tsnprintf(tmpDir, sizeof(tmpDir) / sizeof(tmpDir[0]), NS_T("%s.bak"),
               destDir);

  NS_tchar newDir[MAXPATHLEN];
  NS_tsnprintf(newDir, sizeof(newDir) / sizeof(newDir[0]),
#ifdef XP_MACOSX
               NS_T("%s/Contents"), gWorkingDirPath);
#else
               NS_T("%s.bak/updated"), gInstallDirPath);
#endif

  // First try to remove the possibly existing temp directory, because if this
  // directory exists, we will fail to rename destDir.
  // No need to error check here because if this fails, we will fail in the
  // next step anyways.
  ensure_remove_recursive(tmpDir);

  LOG(("Begin moving destDir (" LOG_S ") to tmpDir (" LOG_S ")", destDir,
       tmpDir));
  int rv = rename_file(destDir, tmpDir, true);
#ifdef XP_WIN
  // On Windows, if Firefox is launched using the shortcut, it will hold a
  // handle to its installation directory open, which might not get released in
  // time. Therefore we wait a little bit here to see if the handle is released.
  // If it's not released, we just fail to perform the replace request.
  const int max_retries = 10;
  int retries = 0;
  while (rv == WRITE_ERROR && (retries++ < max_retries)) {
    LOG(
        ("PerformReplaceRequest: destDir rename attempt %d failed. "
         "File: " LOG_S ". Last error: %d, err: %d",
         retries, destDir, GetLastError(), rv));

    Sleep(100);

    rv = rename_file(destDir, tmpDir, true);
  }
#endif
  if (rv) {
    // The status file will have 'pending' written to it so there is no value in
    // returning an error specific for this failure.
    LOG(("Moving destDir to tmpDir failed, err: %d", rv));
    return rv;
  }

  LOG(("Begin moving newDir (" LOG_S ") to destDir (" LOG_S ")", newDir,
       destDir));
  rv = rename_file(newDir, destDir, true);
#ifdef XP_MACOSX
  if (rv) {
    LOG(("Moving failed. Begin copying newDir (" LOG_S ") to destDir (" LOG_S
         ")",
         newDir, destDir));
    copy_recursive_skiplist<0> skiplist;
    rv = ensure_copy_recursive(newDir, destDir, skiplist);
  }
#endif
  if (rv) {
    LOG(("Moving newDir to destDir failed, err: %d", rv));
    LOG(("Now, try to move tmpDir back to destDir"));
    ensure_remove_recursive(destDir);
    int rv2 = rename_file(tmpDir, destDir, true);
    if (rv2) {
      LOG(("Moving tmpDir back to destDir failed, err: %d", rv2));
    }
    // The status file will be have 'pending' written to it so there is no value
    // in returning an error specific for this failure.
    return rv;
  }

#if !defined(XP_WIN) && !defined(XP_MACOSX)
  // Platforms that have their updates directory in the installation directory
  // need to have the last-update.log and backup-update.log files moved from the
  // old installation directory to the new installation directory.
  NS_tchar tmpLog[MAXPATHLEN];
  NS_tsnprintf(tmpLog, sizeof(tmpLog) / sizeof(tmpLog[0]),
               NS_T("%s/updates/last-update.log"), tmpDir);
  if (!NS_taccess(tmpLog, F_OK)) {
    NS_tchar destLog[MAXPATHLEN];
    NS_tsnprintf(destLog, sizeof(destLog) / sizeof(destLog[0]),
                 NS_T("%s/updates/last-update.log"), destDir);
    if (NS_tremove(destLog) && errno != ENOENT) {
      LOG(("non-fatal error removing log file: " LOG_S ", err: %d", destLog,
           errno));
    }
    NS_trename(tmpLog, destLog);
  }
#endif

  LOG(("Now, remove the tmpDir"));
  rv = ensure_remove_recursive(tmpDir, true);
  if (rv) {
    LOG(("Removing tmpDir failed, err: %d", rv));
#ifdef XP_WIN
    NS_tchar deleteDir[MAXPATHLEN];
    NS_tsnprintf(deleteDir, sizeof(deleteDir) / sizeof(deleteDir[0]),
                 NS_T("%s\\%s"), destDir, DELETE_DIR);
    // Attempt to remove the tobedeleted directory and then recreate it if it
    // was successfully removed.
    _wrmdir(deleteDir);
    if (NS_taccess(deleteDir, F_OK)) {
      NS_tmkdir(deleteDir, 0755);
    }
    remove_recursive_on_reboot(tmpDir, deleteDir);
#endif
  }

#ifdef XP_MACOSX
  // On OS X, we we need to remove the staging directory after its Contents
  // directory has been moved.
  NS_tchar updatedAppDir[MAXPATHLEN];
  NS_tsnprintf(updatedAppDir, sizeof(updatedAppDir) / sizeof(updatedAppDir[0]),
               NS_T("%s/Updated.app"), gPatchDirPath);
  ensure_remove_recursive(updatedAppDir);
#endif

  gSucceeded = true;

  return 0;
}

#if defined(XP_WIN) && defined(MOZ_MAINTENANCE_SERVICE)
static void WaitForServiceFinishThread(void* param) {
  // We wait at most 10 minutes, we already waited 5 seconds previously
  // before deciding to show this UI.
  WaitForServiceStop(SVC_NAME, 595);
  QuitProgressUI();
}
#endif

#ifdef MOZ_VERIFY_MAR_SIGNATURE
/**
 * This function reads in the ACCEPTED_MAR_CHANNEL_IDS from update-settings.ini
 *
 * @param path    The path to the ini file that is to be read
 * @param results A pointer to the location to store the read strings
 * @return OK on success
 */
static int ReadMARChannelIDs(const NS_tchar* path,
                             MARChannelStringTable* results) {
  const unsigned int kNumStrings = 1;
  const char* kUpdaterKeys = "ACCEPTED_MAR_CHANNEL_IDS\0";
  char updater_strings[kNumStrings][MAX_TEXT_LEN];

  int result =
      ReadStrings(path, kUpdaterKeys, kNumStrings, updater_strings, "Settings");

  strncpy(results->MARChannelID, updater_strings[0], MAX_TEXT_LEN - 1);
  results->MARChannelID[MAX_TEXT_LEN - 1] = 0;

  return result;
}
#endif

static int GetUpdateFileName(NS_tchar* fileName, int maxChars) {
  NS_tsnprintf(fileName, maxChars, NS_T("%s/update.mar"), gPatchDirPath);
  return OK;
}

static void UpdateThreadFunc(void* param) {
  // open ZIP archive and process...
  int rv;
  if (sReplaceRequest) {
    rv = ProcessReplaceRequest();
  } else {
    NS_tchar dataFile[MAXPATHLEN];
    rv = GetUpdateFileName(dataFile, sizeof(dataFile) / sizeof(dataFile[0]));
    if (rv == OK) {
      rv = gArchiveReader.Open(dataFile);
    }

#ifdef MOZ_VERIFY_MAR_SIGNATURE
    if (rv == OK) {
      rv = gArchiveReader.VerifySignature();
    }

    if (rv == OK) {
      if (rv == OK) {
        NS_tchar updateSettingsPath[MAX_TEXT_LEN];
        NS_tsnprintf(updateSettingsPath,
                     sizeof(updateSettingsPath) / sizeof(updateSettingsPath[0]),
#  ifdef XP_MACOSX
                     NS_T("%s/Contents/Resources/update-settings.ini"),
#  else
                     NS_T("%s/update-settings.ini"),
#  endif
                     gInstallDirPath);
        MARChannelStringTable MARStrings;
        if (ReadMARChannelIDs(updateSettingsPath, &MARStrings) != OK) {
          rv = UPDATE_SETTINGS_FILE_CHANNEL;
        } else {
          rv = gArchiveReader.VerifyProductInformation(MARStrings.MARChannelID,
                                                       MOZ_APP_VERSION);
        }
      }
    }
#endif

    if (rv == OK && sStagedUpdate) {
#ifdef TEST_UPDATER
      // The MOZ_TEST_SKIP_UPDATE_STAGE environment variable prevents copying
      // the files in dist/bin in the test updater when staging an update since
      // this can cause tests to timeout.
      if (EnvHasValue("MOZ_TEST_SKIP_UPDATE_STAGE")) {
        rv = OK;
      } else if (EnvHasValue("MOZ_TEST_SLOW_SKIP_UPDATE_STAGE")) {
        // The following is to simulate staging so the UI tests have time to
        // show that the update is being staged.
        NS_tchar continueFilePath[MAXPATHLEN] = {NS_T('\0')};
        NS_tsnprintf(continueFilePath,
                     sizeof(continueFilePath) / sizeof(continueFilePath[0]),
                     NS_T("%s/continueStaging"), gInstallDirPath);
        // Use 300 retries for staging requests to lessen the likelihood of
        // tests intermittently failing on verify tasks due to launching the
        // updater. The total time to wait with the default interval of 100 ms
        // is approximately 30 seconds. The total time for tests is longer to
        // account for the extra time it takes for the updater to launch.
        const int max_retries = 300;
        int retries = 0;
        while (retries++ < max_retries) {
#  ifdef XP_WIN
          Sleep(100);
#  else
          usleep(100000);
#  endif
          // Continue after the continue file exists and is removed.
          if (!NS_tremove(continueFilePath)) {
            break;
          }
        }
        rv = OK;
      } else {
        rv = CopyInstallDirToDestDir();
      }
#else
      rv = CopyInstallDirToDestDir();
#endif
    }

    if (rv == OK) {
      rv = DoUpdate();
      gArchiveReader.Close();
      NS_tchar updatingDir[MAXPATHLEN];
      NS_tsnprintf(updatingDir, sizeof(updatingDir) / sizeof(updatingDir[0]),
                   NS_T("%s/updating"), gWorkingDirPath);
      ensure_remove_recursive(updatingDir);
    }
  }

  if (rv && (sReplaceRequest || sStagedUpdate)) {
    ensure_remove_recursive(gWorkingDirPath);
    // When attempting to replace the application, we should fall back
    // to non-staged updates in case of a failure.  We do this by
    // setting the status to pending, exiting the updater, and
    // launching the callback application.  The callback application's
    // startup path will see the pending status, and will start the
    // updater application again in order to apply the update without
    // staging.
    if (sReplaceRequest) {
      WriteStatusFile(sUsingService ? "pending-service" : "pending");
    } else {
      WriteStatusFile(rv);
    }
    LOG(("failed: %d", rv));
#ifdef TEST_UPDATER
    // Some tests need to use --test-process-updates again.
    putenv(const_cast<char*>("MOZ_TEST_PROCESS_UPDATES="));
#endif
  } else {
    if (rv) {
      LOG(("failed: %d", rv));
    } else {
#ifdef XP_MACOSX
      // If the update was successful we need to update the timestamp on the
      // top-level Mac OS X bundle directory so that Mac OS X's Launch Services
      // picks up any major changes when the bundle is updated.
      if (!sStagedUpdate && utimes(gInstallDirPath, nullptr) != 0) {
        LOG(("Couldn't set access/modification time on application bundle."));
      }
#endif
      LOG(("succeeded"));
    }
    WriteStatusFile(rv);
  }

  LOG(("calling QuitProgressUI"));
  QuitProgressUI();
}

#ifdef XP_MACOSX
static void ServeElevatedUpdateThreadFunc(void* param) {
  UpdateServerThreadArgs* threadArgs = (UpdateServerThreadArgs*)param;
  gSucceeded = ServeElevatedUpdate(threadArgs->argc, threadArgs->argv);
  if (!gSucceeded) {
    WriteStatusFile(ELEVATION_CANCELED);
  }
  QuitProgressUI();
}

void freeArguments(int argc, char** argv) {
  for (int i = 0; i < argc; i++) {
    free(argv[i]);
  }
  free(argv);
}
#endif

int LaunchCallbackAndPostProcessApps(int argc, NS_tchar** argv,
                                     int callbackIndex
#ifdef XP_WIN
                                     ,
                                     const WCHAR* elevatedLockFilePath,
                                     HANDLE updateLockFileHandle
#elif XP_MACOSX
                                     ,
                                     bool isElevated
#endif
) {
  if (argc > callbackIndex) {
#if defined(XP_WIN)
    if (gSucceeded) {
      if (!LaunchWinPostProcess(gInstallDirPath, gPatchDirPath)) {
        fprintf(stderr, "The post update process was not launched");
      }

#  ifdef MOZ_MAINTENANCE_SERVICE
      // The service update will only be executed if it is already installed.
      // For first time installs of the service, the install will happen from
      // the PostUpdate process. We do the service update process here
      // because it's possible we are updating with updater.exe without the
      // service if the service failed to apply the update. We want to update
      // the service to a newer version in that case. If we are not running
      // through the service, then MOZ_USING_SERVICE will not exist.
      if (!sUsingService) {
        StartServiceUpdate(gInstallDirPath);
      }
#  endif
    }
    EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 0);
#elif XP_MACOSX
    if (!isElevated) {
      if (gSucceeded) {
        LaunchMacPostProcess(gInstallDirPath);
      }
#endif

    LaunchCallbackApp(argv[5], argc - callbackIndex, argv + callbackIndex,
                      sUsingService);
#ifdef XP_MACOSX
  }    // if (!isElevated)
#endif /* XP_MACOSX */
}
return 0;
}

int NS_main(int argc, NS_tchar** argv) {
#ifdef MOZ_MAINTENANCE_SERVICE
  sUsingService = EnvHasValue("MOZ_USING_SERVICE");
  putenv(const_cast<char*>("MOZ_USING_SERVICE="));
#endif

  // The callback is the remaining arguments starting at callbackIndex.
  // The argument specified by callbackIndex is the callback executable and the
  // argument prior to callbackIndex is the working directory.
  const int callbackIndex = 6;

#ifdef XP_MACOSX
  // We want to control file permissions explicitly, or else we could end up
  // corrupting installs for other users on the system. Accordingly, set the
  // umask to 0 for all file creations below and reset it on exit. See Bug
  // 1337007
  UmaskContext umaskContext(0);

  bool isElevated =
      strstr(argv[0], "/Library/PrivilegedHelperTools/org.mozilla.updater") !=
      0;
  if (isElevated) {
    if (!ObtainUpdaterArguments(&argc, &argv)) {
      // Won't actually get here because ObtainUpdaterArguments will terminate
      // the current process on failure.
      return 1;
    }
  }
#endif

#if defined(MOZ_VERIFY_MAR_SIGNATURE) && !defined(XP_WIN) && !defined(XP_MACOSX)
  // On Windows and Mac we rely on native APIs to do verifications so we don't
  // need to initialize NSS at all there.
  // Otherwise, minimize the amount of NSS we depend on by avoiding all the NSS
  // databases.
  if (NSS_NoDB_Init(nullptr) != SECSuccess) {
    PRErrorCode error = PR_GetError();
    fprintf(stderr, "Could not initialize NSS: %s (%d)", PR_ErrorToName(error),
            (int)error);
    _exit(1);
  }
#endif

#ifdef XP_MACOSX
  if (!isElevated) {
#endif
    InitProgressUI(&argc, &argv);
#ifdef XP_MACOSX
  }
#endif

  // To process an update the updater command line must at a minimum have the
  // directory path containing the updater.mar file to process as the first
  // argument, the install directory as the second argument, and the directory
  // to apply the update to as the third argument. When the updater is launched
  // by another process the PID of the parent process should be provided in the
  // optional fourth argument and the updater will wait on the parent process to
  // exit if the value is non-zero and the process is present. This is necessary
  // due to not being able to update files that are in use on Windows. The
  // optional fifth argument is the callback's working directory and the
  // optional sixth argument is the callback path. The callback is the
  // application to launch after updating and it will be launched when these
  // arguments are provided whether the update was successful or not. All
  // remaining arguments are optional and are passed to the callback when it is
  // launched.
  if (argc < 4) {
    fprintf(stderr,
            "Usage: updater patch-dir install-dir apply-to-dir [wait-pid "
            "[callback-working-dir callback-path args...]]\n");
#ifdef XP_MACOSX
    if (isElevated) {
      freeArguments(argc, argv);
      CleanupElevatedMacUpdate(true);
    }
#endif
    return 1;
  }

#if defined(TEST_UPDATER) && defined(XP_WIN)
  // The tests use nsIProcess to launch the updater and it is simpler for the
  // tests to just set an environment variable and have the test updater set
  // the current working directory than it is to set the current working
  // directory in the test itself.
  if (EnvHasValue("CURWORKDIRPATH")) {
    const WCHAR* val = _wgetenv(L"CURWORKDIRPATH");
    NS_tchdir(val);
  }
#endif

  // This check is also performed in workmonitor.cpp since the maintenance
  // service can be called directly.
  if (!IsValidFullPath(argv[1])) {
    // Since the status file is written to the patch directory and the patch
    // directory is invalid don't write the status file.
    fprintf(stderr,
            "The patch directory path is not valid for this "
            "application (" LOG_S ")\n",
            argv[1]);
#ifdef XP_MACOSX
    if (isElevated) {
      freeArguments(argc, argv);
      CleanupElevatedMacUpdate(true);
    }
#endif
    return 1;
  }
  // The directory containing the update information.
  NS_tstrncpy(gPatchDirPath, argv[1], MAXPATHLEN);
  gPatchDirPath[MAXPATHLEN - 1] = NS_T('\0');

#ifdef XP_WIN
  NS_tchar elevatedLockFilePath[MAXPATHLEN] = {NS_T('\0')};
  NS_tsnprintf(elevatedLockFilePath,
               sizeof(elevatedLockFilePath) / sizeof(elevatedLockFilePath[0]),
               NS_T("%s\\update_elevated.lock"), gPatchDirPath);
  gUseSecureOutputPath =
      sUsingService || (NS_tremove(elevatedLockFilePath) && errno != ENOENT);
#endif

  // This check is also performed in workmonitor.cpp since the maintenance
  // service can be called directly.
  if (!IsValidFullPath(argv[2])) {
    WriteStatusFile(INVALID_INSTALL_DIR_PATH_ERROR);
    fprintf(stderr,
            "The install directory path is not valid for this "
            "application (" LOG_S ")\n",
            argv[2]);
#ifdef XP_MACOSX
    if (isElevated) {
      freeArguments(argc, argv);
      CleanupElevatedMacUpdate(true);
    }
#endif
    return 1;
  }
  // The directory we're going to update to.
  // We copy this string because we need to remove trailing slashes.  The C++
  // standard says that it's always safe to write to strings pointed to by argv
  // elements, but I don't necessarily believe it.
  NS_tstrncpy(gInstallDirPath, argv[2], MAXPATHLEN);
  gInstallDirPath[MAXPATHLEN - 1] = NS_T('\0');
  NS_tchar* slash = NS_tstrrchr(gInstallDirPath, NS_SLASH);
  if (slash && !slash[1]) {
    *slash = NS_T('\0');
  }

#ifdef XP_WIN
  bool useService = false;
  bool testOnlyFallbackKeyExists = false;
  bool noServiceFallback = false;

  // We never want the service to be used unless we build with
  // the maintenance service.
#  ifdef MOZ_MAINTENANCE_SERVICE
  useService = IsUpdateStatusPendingService();
#    ifdef TEST_UPDATER
  noServiceFallback = EnvHasValue("MOZ_NO_SERVICE_FALLBACK");
  putenv(const_cast<char*>("MOZ_NO_SERVICE_FALLBACK="));
  // Our tests run with a different apply directory for each test.
  // We use this registry key on our test slaves to store the
  // allowed name/issuers.
  testOnlyFallbackKeyExists = DoesFallbackKeyExist();
#    endif
#  endif

  // Remove everything except close window from the context menu
  {
    HKEY hkApp = nullptr;
    RegCreateKeyExW(HKEY_CURRENT_USER, L"Software\\Classes\\Applications", 0,
                    nullptr, REG_OPTION_NON_VOLATILE, KEY_SET_VALUE, nullptr,
                    &hkApp, nullptr);
    RegCloseKey(hkApp);
    if (RegCreateKeyExW(HKEY_CURRENT_USER,
                        L"Software\\Classes\\Applications\\updater.exe", 0,
                        nullptr, REG_OPTION_VOLATILE, KEY_SET_VALUE, nullptr,
                        &hkApp, nullptr) == ERROR_SUCCESS) {
      RegSetValueExW(hkApp, L"IsHostApp", 0, REG_NONE, 0, 0);
      RegSetValueExW(hkApp, L"NoOpenWith", 0, REG_NONE, 0, 0);
      RegSetValueExW(hkApp, L"NoStartPage", 0, REG_NONE, 0, 0);
      RegCloseKey(hkApp);
    }
  }
#endif

  // If there is a PID specified and it is not '0' then wait for the process to
  // exit.
  NS_tpid pid = 0;
  if (argc > 4) {
    pid = NS_tatoi(argv[4]);
    if (pid == -1) {
      // This is a signal from the parent process that the updater should stage
      // the update.
      sStagedUpdate = true;
    } else if (NS_tstrstr(argv[4], NS_T("/replace"))) {
      // We're processing a request to replace the application with a staged
      // update.
      sReplaceRequest = true;
    }
  }

  // This check is also performed in workmonitor.cpp since the maintenance
  // service can be called directly.
  if (!IsValidFullPath(argv[3])) {
    WriteStatusFile(INVALID_WORKING_DIR_PATH_ERROR);
    fprintf(stderr,
            "The working directory path is not valid for this "
            "application (" LOG_S ")\n",
            argv[3]);
#ifdef XP_MACOSX
    if (isElevated) {
      freeArguments(argc, argv);
      CleanupElevatedMacUpdate(true);
    }
#endif
    return 1;
  }
  // The directory we're going to update to.
  // We copy this string because we need to remove trailing slashes.  The C++
  // standard says that it's always safe to write to strings pointed to by argv
  // elements, but I don't necessarily believe it.
  NS_tstrncpy(gWorkingDirPath, argv[3], MAXPATHLEN);
  gWorkingDirPath[MAXPATHLEN - 1] = NS_T('\0');
  slash = NS_tstrrchr(gWorkingDirPath, NS_SLASH);
  if (slash && !slash[1]) {
    *slash = NS_T('\0');
  }

  if (argc > callbackIndex) {
    if (!IsValidFullPath(argv[callbackIndex])) {
      WriteStatusFile(INVALID_CALLBACK_PATH_ERROR);
      fprintf(stderr,
              "The callback file path is not valid for this "
              "application (" LOG_S ")\n",
              argv[callbackIndex]);
#ifdef XP_MACOSX
      if (isElevated) {
        freeArguments(argc, argv);
        CleanupElevatedMacUpdate(true);
      }
#endif
      return 1;
    }

    size_t len = NS_tstrlen(gInstallDirPath);
    NS_tchar callbackInstallDir[MAXPATHLEN] = {NS_T('\0')};
    NS_tstrncpy(callbackInstallDir, argv[callbackIndex], len);
    if (NS_tstrcmp(gInstallDirPath, callbackInstallDir) != 0) {
      WriteStatusFile(INVALID_CALLBACK_DIR_ERROR);
      fprintf(stderr,
              "The callback file must be located in the "
              "installation directory (" LOG_S ")\n",
              argv[callbackIndex]);
#ifdef XP_MACOSX
      if (isElevated) {
        freeArguments(argc, argv);
        CleanupElevatedMacUpdate(true);
      }
#endif
      return 1;
    }
  }

#ifdef XP_MACOSX
  if (!isElevated && !IsRecursivelyWritable(argv[2])) {
    // If the app directory isn't recursively writeable, an elevated update is
    // required.
    UpdateServerThreadArgs threadArgs;
    threadArgs.argc = argc;
    threadArgs.argv = const_cast<const NS_tchar**>(argv);

    Thread t1;
    if (t1.Run(ServeElevatedUpdateThreadFunc, &threadArgs) == 0) {
      // Show an indeterminate progress bar while an elevated update is in
      // progress.
      ShowProgressUI(true);
    }
    t1.Join();

    LaunchCallbackAndPostProcessApps(argc, argv, callbackIndex, false);
    return gSucceeded ? 0 : 1;
  }
#endif

  NS_tchar logFilePath[MAXPATHLEN + 1] = {L'\0'};
#ifdef XP_WIN
  if (gUseSecureOutputPath) {
    // Remove the secure output files so it is easier to determine when new
    // files are created in the unelevated updater.
    RemoveSecureOutputFiles(gPatchDirPath);

    (void)GetSecureOutputFilePath(gPatchDirPath, L".log", logFilePath);
  } else {
    NS_tsnprintf(logFilePath, sizeof(logFilePath) / sizeof(logFilePath[0]),
                 NS_T("%s\\update.log"), gPatchDirPath);
  }
#else
    NS_tsnprintf(logFilePath, sizeof(logFilePath) / sizeof(logFilePath[0]),
                 NS_T("%s/update.log"), gPatchDirPath);
#endif
  LogInit(logFilePath);

  if (!WriteStatusFile("applying")) {
    LOG(("failed setting status to 'applying'"));
#ifdef XP_MACOSX
    if (isElevated) {
      freeArguments(argc, argv);
      CleanupElevatedMacUpdate(true);
    }
#endif
    output_finish();
    return 1;
  }

  if (sStagedUpdate) {
    LOG(("Performing a staged update"));
  } else if (sReplaceRequest) {
    LOG(("Performing a replace request"));
  }

  LOG(("PATCH DIRECTORY " LOG_S, gPatchDirPath));
  LOG(("INSTALLATION DIRECTORY " LOG_S, gInstallDirPath));
  LOG(("WORKING DIRECTORY " LOG_S, gWorkingDirPath));

#if defined(XP_WIN)
  // These checks are also performed in workmonitor.cpp since the maintenance
  // service can be called directly.
  if (_wcsnicmp(gWorkingDirPath, gInstallDirPath, MAX_PATH) != 0) {
    if (!sStagedUpdate && !sReplaceRequest) {
      WriteStatusFile(INVALID_APPLYTO_DIR_ERROR);
      LOG(
          ("Installation directory and working directory must be the same "
           "for non-staged updates. Exiting."));
      output_finish();
      return 1;
    }

    NS_tchar workingDirParent[MAX_PATH];
    NS_tsnprintf(workingDirParent,
                 sizeof(workingDirParent) / sizeof(workingDirParent[0]),
                 NS_T("%s"), gWorkingDirPath);
    if (!PathRemoveFileSpecW(workingDirParent)) {
      WriteStatusFile(REMOVE_FILE_SPEC_ERROR);
      LOG(("Error calling PathRemoveFileSpecW: %d", GetLastError()));
      output_finish();
      return 1;
    }

    if (_wcsnicmp(workingDirParent, gInstallDirPath, MAX_PATH) != 0) {
      WriteStatusFile(INVALID_APPLYTO_DIR_STAGED_ERROR);
      LOG(
          ("The apply-to directory must be the same as or "
           "a child of the installation directory! Exiting."));
      output_finish();
      return 1;
    }
  }
#endif

#ifdef XP_WIN
  if (pid > 0) {
    HANDLE parent = OpenProcess(SYNCHRONIZE, false, (DWORD)pid);
    // May return nullptr if the parent process has already gone away.
    // Otherwise, wait for the parent process to exit before starting the
    // update.
    if (parent) {
      DWORD waitTime = PARENT_WAIT;
#  ifdef TEST_UPDATER
      if (EnvHasValue("MOZ_TEST_SHORTER_WAIT_PID")) {
        // Use a shorter time to wait for the PID to exit for the test.
        waitTime = 100;
      }
#  endif
      DWORD result = WaitForSingleObject(parent, waitTime);
      CloseHandle(parent);
      if (result != WAIT_OBJECT_0) {
        // Continue to update since the parent application sometimes doesn't
        // exit (see bug 1375242) so any fixes to the parent application will
        // be applied instead of leaving the client in a broken state.
        LOG(("The parent process didn't exit! Continuing with update."));
      }
    }
  }
#endif

#ifdef XP_WIN
  if (sReplaceRequest || sStagedUpdate) {
    // On Windows, when performing a stage or replace request the current
    // working directory for the process must be changed so it isn't locked.
    NS_tchar sysDir[MAX_PATH + 1] = {L'\0'};
    if (GetSystemDirectoryW(sysDir, MAX_PATH + 1)) {
      NS_tchdir(sysDir);
    }
  }

  // lastFallbackError keeps track of the last error for the service not being
  // used, in case of an error when fallback is not enabled we write the
  // error to the update.status file.
  // When fallback is disabled (MOZ_NO_SERVICE_FALLBACK does not exist) then
  // we will instead fallback to not using the service and display a UAC prompt.
  int lastFallbackError = FALLBACKKEY_UNKNOWN_ERROR;

  // Check whether a second instance of the updater should be launched by the
  // maintenance service or with the 'runas' verb when write access is denied to
  // the installation directory and the update isn't being staged.
  HANDLE updateLockFileHandle = INVALID_HANDLE_VALUE;
  if (!sUsingService &&
      (argc > callbackIndex || sStagedUpdate || sReplaceRequest)) {
    NS_tchar updateLockFilePath[MAXPATHLEN];
    if (sStagedUpdate) {
      // When staging an update, the lock file is:
      // <install_dir>\updated.update_in_progress.lock
      NS_tsnprintf(updateLockFilePath,
                   sizeof(updateLockFilePath) / sizeof(updateLockFilePath[0]),
                   NS_T("%s/updated.update_in_progress.lock"), gInstallDirPath);
    } else if (sReplaceRequest) {
      // When processing a replace request, the lock file is:
      // <install_dir>\..\moz_update_in_progress.lock
      NS_tchar installDir[MAXPATHLEN];
      NS_tstrcpy(installDir, gInstallDirPath);
      NS_tchar* slash = (NS_tchar*)NS_tstrrchr(installDir, NS_SLASH);
      *slash = NS_T('\0');
      NS_tsnprintf(updateLockFilePath,
                   sizeof(updateLockFilePath) / sizeof(updateLockFilePath[0]),
                   NS_T("%s\\moz_update_in_progress.lock"), installDir);
    } else {
      // In the non-staging update case, the lock file is:
      // <install_dir>\<app_name>.exe.update_in_progress.lock
      NS_tsnprintf(updateLockFilePath,
                   sizeof(updateLockFilePath) / sizeof(updateLockFilePath[0]),
                   NS_T("%s.update_in_progress.lock"), argv[callbackIndex]);
    }

    // The update_in_progress.lock file should only exist during an update. In
    // case it exists attempt to remove it and exit if that fails to prevent
    // simultaneous updates occurring.
    if (NS_tremove(updateLockFilePath) && errno != ENOENT) {
      // Try to fall back to the old way of doing updates if a staged
      // update fails.
      if (sReplaceRequest) {
        // Note that this could fail, but if it does, there isn't too much we
        // can do in order to recover anyways.
        WriteStatusFile("pending");
      } else if (sStagedUpdate) {
        WriteStatusFile(DELETE_ERROR_STAGING_LOCK_FILE);
      }
      LOG(("Update already in progress! Exiting"));
      output_finish();
      return 1;
    }

    updateLockFileHandle =
        CreateFileW(updateLockFilePath, GENERIC_READ | GENERIC_WRITE, 0,
                    nullptr, OPEN_ALWAYS, FILE_FLAG_DELETE_ON_CLOSE, nullptr);

    // Even if a file has no sharing access, you can still get its attributes
    bool startedFromUnelevatedUpdater =
        GetFileAttributesW(elevatedLockFilePath) != INVALID_FILE_ATTRIBUTES;

    // If we're running from the service, then we were started with the same
    // token as the service so the permissions are already dropped.  If we're
    // running from an elevated updater that was started from an unelevated
    // updater, then we drop the permissions here. We do not drop the
    // permissions on the originally called updater because we use its token
    // to start the callback application.
    if (startedFromUnelevatedUpdater) {
      // Disable every privilege we don't need. Processes started using
      // CreateProcess will use the same token as this process.
      UACHelper::DisablePrivileges(nullptr);
    }

    if (updateLockFileHandle == INVALID_HANDLE_VALUE ||
        (useService && testOnlyFallbackKeyExists && noServiceFallback)) {
      HANDLE elevatedFileHandle;
      if (NS_tremove(elevatedLockFilePath) && errno != ENOENT) {
        LOG(("Unable to create elevated lock file! Exiting"));
        output_finish();
        return 1;
      }

      elevatedFileHandle =
          CreateFileW(elevatedLockFilePath, GENERIC_READ | GENERIC_WRITE, 0,
                      nullptr, OPEN_ALWAYS, FILE_FLAG_DELETE_ON_CLOSE, nullptr);
      if (elevatedFileHandle == INVALID_HANDLE_VALUE) {
        LOG(("Unable to create elevated lock file! Exiting"));
        output_finish();
        return 1;
      }

      auto cmdLine = mozilla::MakeCommandLine(argc - 1, argv + 1);
      if (!cmdLine) {
        CloseHandle(elevatedFileHandle);
        output_finish();
        return 1;
      }

#  ifdef MOZ_MAINTENANCE_SERVICE
// Only invoke the service for installations in Program Files.
// This check is duplicated in workmonitor.cpp because the service can
// be invoked directly without going through the updater.
#    ifndef TEST_UPDATER
      if (useService) {
        useService = IsProgramFilesPath(gInstallDirPath);
      }
#    endif

      // Make sure the path to the updater to use for the update is on local.
      // We do this check to make sure that file locking is available for
      // race condition security checks.
      if (useService) {
        BOOL isLocal = FALSE;
        useService = IsLocalFile(argv[0], isLocal) && isLocal;
      }

      // If we have unprompted elevation we should NOT use the service
      // for the update. Service updates happen with the SYSTEM account
      // which has more privs than we need to update with.
      // Windows 8 provides a user interface so users can configure this
      // behavior and it can be configured in the registry in all Windows
      // versions that support UAC.
      if (useService) {
        BOOL unpromptedElevation;
        if (IsUnpromptedElevation(unpromptedElevation)) {
          useService = !unpromptedElevation;
        }
      }

      // Make sure the service registry entries for the instsallation path
      // are available.  If not don't use the service.
      if (useService) {
        WCHAR maintenanceServiceKey[MAX_PATH + 1];
        if (CalculateRegistryPathFromFilePath(gInstallDirPath,
                                              maintenanceServiceKey)) {
          HKEY baseKey = nullptr;
          if (RegOpenKeyExW(HKEY_LOCAL_MACHINE, maintenanceServiceKey, 0,
                            KEY_READ | KEY_WOW64_64KEY,
                            &baseKey) == ERROR_SUCCESS) {
            RegCloseKey(baseKey);
          } else {
#    ifdef TEST_UPDATER
            useService = testOnlyFallbackKeyExists;
#    endif
            if (!useService) {
              lastFallbackError = FALLBACKKEY_NOKEY_ERROR;
            }
          }
        } else {
          useService = false;
          lastFallbackError = FALLBACKKEY_REGPATH_ERROR;
        }
      }

      // Originally we used to write "pending" to update.status before
      // launching the service command.  This is no longer needed now
      // since the service command is launched from updater.exe.  If anything
      // fails in between, we can fall back to using the normal update process
      // on our own.

      // If we still want to use the service try to launch the service
      // comamnd for the update.
      if (useService) {
        // Get the secure ID before trying to update so it is possible to
        // determine if the updater or the maintenance service has created a
        // new one.
        char uuidStringBefore[UUID_LEN] = {'\0'};
        bool checkID = GetSecureID(uuidStringBefore);
        // Write a catchall service failure status in case it fails without
        // changing the status.
        WriteStatusFile(SERVICE_UPDATE_STATUS_UNCHANGED);

        // If the update couldn't be started, then set useService to false so
        // we do the update the old way.
        DWORD ret = LaunchServiceSoftwareUpdateCommand(argc, (LPCWSTR*)argv);
        useService = (ret == ERROR_SUCCESS);
        // If the command was launched then wait for the service to be done.
        if (useService) {
          bool showProgressUI = false;
          // Never show the progress UI when staging updates.
          if (!sStagedUpdate) {
            // We need to call this separately instead of allowing
            // ShowProgressUI to initialize the strings because the service will
            // move the ini file out of the way when running updater.
            showProgressUI = !InitProgressUIStrings();
          }

          // Wait for the service to stop for 5 seconds.  If the service
          // has still not stopped then show an indeterminate progress bar.
          DWORD lastState = WaitForServiceStop(SVC_NAME, 5);
          if (lastState != SERVICE_STOPPED) {
            Thread t1;
            if (t1.Run(WaitForServiceFinishThread, nullptr) == 0 &&
                showProgressUI) {
              ShowProgressUI(true, false);
            }
            t1.Join();
          }

          lastState = WaitForServiceStop(SVC_NAME, 1);
          if (lastState != SERVICE_STOPPED) {
            // If the service doesn't stop after 10 minutes there is
            // something seriously wrong.
            lastFallbackError = FALLBACKKEY_SERVICE_NO_STOP_ERROR;
            useService = false;
          } else {
            // Copy the secure output files if the secure ID has changed.
            gCopyOutputFiles = true;
            char uuidStringAfter[UUID_LEN] = {'\0'};
            if (checkID && GetSecureID(uuidStringAfter) &&
                strncmp(uuidStringBefore, uuidStringAfter,
                        sizeof(uuidStringBefore)) == 0) {
              LOG(
                  ("The secure ID hasn't changed after launching the updater "
                   "using the service"));
              gCopyOutputFiles = false;
            }
          }
        } else {
          lastFallbackError = FALLBACKKEY_LAUNCH_ERROR;
        }
      }
#  endif

      // If the service can't be used when staging an update, make sure that
      // the UAC prompt is not shown! In this case, just set the status to
      // pending and the update will be applied during the next startup.
      if (!useService && sStagedUpdate) {
        if (updateLockFileHandle != INVALID_HANDLE_VALUE) {
          CloseHandle(updateLockFileHandle);
        }
        WriteStatusFile(UNEXPECTED_STAGING_ERROR);
        LOG(
            ("Non-critical update staging error! Falling back to non-staged "
             "updates and exiting"));
        output_finish();
        return 0;
      }

#  ifdef MOZ_MAINTENANCE_SERVICE
      // If we started the service command, and it finished, check the secure
      // update status file to make sure that it succeeded, and if it did we
      // need to launch the PostUpdate process in the unelevated updater which
      // is running in the current user's session. Note that we don't need to do
      // this when staging an update since the PostUpdate step runs during the
      // replace request.
      if (useService && !sStagedUpdate) {
        bool updateStatusSucceeded = false;
        if (IsSecureUpdateStatusSucceeded(updateStatusSucceeded) &&
            updateStatusSucceeded) {
          if (!LaunchWinPostProcess(gInstallDirPath, gPatchDirPath)) {
            fprintf(stderr,
                    "The post update process which runs as the user"
                    " for service update could not be launched.");
          }
        }
      }
#  endif

      // If we didn't want to use the service at all, or if an update was
      // already happening, or launching the service command failed, then
      // launch the elevated updater.exe as we do without the service.
      // We don't launch the elevated updater in the case that we did have
      // write access all along because in that case the only reason we're
      // using the service is because we are testing.
      if (!useService && !noServiceFallback &&
          updateLockFileHandle == INVALID_HANDLE_VALUE) {
        // Get the secure ID before trying to update so it is possible to
        // determine if the updater has created a new one.
        char uuidStringBefore[UUID_LEN] = {'\0'};
        bool checkID = GetSecureID(uuidStringBefore);
        // Write a catchall failure status in case it fails without changing the
        // status.
        WriteStatusFile(UPDATE_STATUS_UNCHANGED);

        SHELLEXECUTEINFO sinfo;
        memset(&sinfo, 0, sizeof(SHELLEXECUTEINFO));
        sinfo.cbSize = sizeof(SHELLEXECUTEINFO);
        sinfo.fMask = SEE_MASK_FLAG_NO_UI | SEE_MASK_FLAG_DDEWAIT |
                      SEE_MASK_NOCLOSEPROCESS;
        sinfo.hwnd = nullptr;
        sinfo.lpFile = argv[0];
        sinfo.lpParameters = cmdLine.get();
        sinfo.lpVerb = L"runas";
        sinfo.nShow = SW_SHOWNORMAL;

        bool result = ShellExecuteEx(&sinfo);

        if (result) {
          WaitForSingleObject(sinfo.hProcess, INFINITE);
          CloseHandle(sinfo.hProcess);

          // Copy the secure output files if the secure ID has changed.
          gCopyOutputFiles = true;
          char uuidStringAfter[UUID_LEN] = {'\0'};
          if (checkID && GetSecureID(uuidStringAfter) &&
              strncmp(uuidStringBefore, uuidStringAfter,
                      sizeof(uuidStringBefore)) == 0) {
            LOG(
                ("The secure ID hasn't changed after launching the updater "
                 "using runas"));
            gCopyOutputFiles = false;
          }
        } else {
          // Don't copy the secure output files if the elevation request was
          // canceled since the status file written below is in the patch
          // directory. At this point it should already be set to false and this
          // is set here to make it clear that it should be false at this point
          // and to prevent future changes from regressing this code.
          gCopyOutputFiles = false;
          WriteStatusFile(ELEVATION_CANCELED);
        }
      }

      // Note: The PostUpdate process is launched by the elevated updater which
      // is running in the current user's session when the update is successful
      // and doesn't need to be launched here by the unelevated updater as is
      // done when the maintenance service launches the updater code above.

      CloseHandle(elevatedFileHandle);

      if (updateLockFileHandle != INVALID_HANDLE_VALUE) {
        CloseHandle(updateLockFileHandle);
      }

      if (!useService && noServiceFallback) {
        // When the service command was not launched at all.
        // We should only reach this code path because we had write access
        // all along to the directory and a fallback key existed, and we
        // have fallback disabled (MOZ_NO_SERVICE_FALLBACK env var exists).
        // We only currently use this env var from XPCShell tests.
        gCopyOutputFiles = false;
        WriteStatusFile(lastFallbackError);
      }

      // The logging output needs to be finished before launching the callback
      // application so the update status file contains the value from the
      // secure directory used by the maintenance service and the elevated
      // updater.
      output_finish();
      if (argc > callbackIndex) {
        LaunchCallbackApp(argv[5], argc - callbackIndex, argv + callbackIndex,
                          sUsingService);
      }
      return 0;

      // This is the end of the code block for launching another instance of the
      // updater using either the maintenance service or with the 'runas' verb
      // when the updater doesn't have write access to the installation
      // directory.
    }
    // This is the end of the code block when the updater was not launched by
    // the service that checks whether the updater has write access to the
    // installation directory.
  }
  // If we made it this far this is the updater instance that will perform the
  // actual update and gCopyOutputFiles will be false (e.g. the default value).
#endif

  if (sStagedUpdate) {
#ifdef TEST_UPDATER
    // This allows testing that the correct UI after an update staging failure
    // that falls back to applying the update on startup. It is simulated due
    // to the difficulty of creating the conditions for this type of staging
    // failure.
    if (EnvHasValue("MOZ_TEST_STAGING_ERROR")) {
#  ifdef XP_WIN
      if (updateLockFileHandle != INVALID_HANDLE_VALUE) {
        CloseHandle(updateLockFileHandle);
      }
#  endif
      // WRITE_ERROR is one of the cases where the staging failure falls back to
      // applying the update on startup.
      WriteStatusFile(WRITE_ERROR);
      output_finish();
      return 0;
    }
#endif
    // When staging updates, blow away the old installation directory and create
    // it from scratch.
    ensure_remove_recursive(gWorkingDirPath);
  }
  if (!sReplaceRequest) {
    // Try to create the destination directory if it doesn't exist
    int rv = NS_tmkdir(gWorkingDirPath, 0755);
    if (rv != OK && errno != EEXIST) {
#ifdef XP_MACOSX
      if (isElevated) {
        freeArguments(argc, argv);
        CleanupElevatedMacUpdate(true);
      }
#endif
      output_finish();
      return 1;
    }
  }

#ifdef XP_WIN
  NS_tchar applyDirLongPath[MAXPATHLEN];
  if (!GetLongPathNameW(
          gWorkingDirPath, applyDirLongPath,
          sizeof(applyDirLongPath) / sizeof(applyDirLongPath[0]))) {
    WriteStatusFile(WRITE_ERROR_APPLY_DIR_PATH);
    LOG(("NS_main: unable to find apply to dir: " LOG_S, gWorkingDirPath));
    output_finish();
    EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 1);
    if (argc > callbackIndex) {
      LaunchCallbackApp(argv[5], argc - callbackIndex, argv + callbackIndex,
                        sUsingService);
    }
    return 1;
  }

  HANDLE callbackFile = INVALID_HANDLE_VALUE;
  if (argc > callbackIndex) {
    // If the callback executable is specified it must exist for a successful
    // update.  It is important we null out the whole buffer here because later
    // we make the assumption that the callback application is inside the
    // apply-to dir.  If we don't have a fully null'ed out buffer it can lead
    // to stack corruption which causes crashes and other problems.
    NS_tchar callbackLongPath[MAXPATHLEN];
    ZeroMemory(callbackLongPath, sizeof(callbackLongPath));
    NS_tchar* targetPath = argv[callbackIndex];
    NS_tchar buffer[MAXPATHLEN * 2] = {NS_T('\0')};
    size_t bufferLeft = MAXPATHLEN * 2;
    if (sReplaceRequest) {
      // In case of replace requests, we should look for the callback file in
      // the destination directory.
      size_t commonPrefixLength =
          PathCommonPrefixW(argv[callbackIndex], gInstallDirPath, nullptr);
      NS_tchar* p = buffer;
      NS_tstrncpy(p, argv[callbackIndex], commonPrefixLength);
      p += commonPrefixLength;
      bufferLeft -= commonPrefixLength;
      NS_tstrncpy(p, gInstallDirPath + commonPrefixLength, bufferLeft);

      size_t len = NS_tstrlen(gInstallDirPath + commonPrefixLength);
      p += len;
      bufferLeft -= len;
      *p = NS_T('\\');
      ++p;
      bufferLeft--;
      *p = NS_T('\0');
      NS_tchar installDir[MAXPATHLEN];
      NS_tstrcpy(installDir, gInstallDirPath);
      size_t callbackPrefixLength =
          PathCommonPrefixW(argv[callbackIndex], installDir, nullptr);
      NS_tstrncpy(p,
                  argv[callbackIndex] +
                      std::max(callbackPrefixLength, commonPrefixLength),
                  bufferLeft);
      targetPath = buffer;
    }
    if (!GetLongPathNameW(
            targetPath, callbackLongPath,
            sizeof(callbackLongPath) / sizeof(callbackLongPath[0]))) {
      WriteStatusFile(WRITE_ERROR_CALLBACK_PATH);
      LOG(("NS_main: unable to find callback file: " LOG_S, targetPath));
      output_finish();
      EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 1);
      if (argc > callbackIndex) {
        LaunchCallbackApp(argv[5], argc - callbackIndex, argv + callbackIndex,
                          sUsingService);
      }
      return 1;
    }

    // Doing this is only necessary when we're actually applying a patch.
    if (!sReplaceRequest) {
      int len = NS_tstrlen(applyDirLongPath);
      NS_tchar* s = callbackLongPath;
      NS_tchar* d = gCallbackRelPath;
      // advance to the apply to directory and advance past the trailing
      // backslash if present.
      s += len;
      if (*s == NS_T('\\')) {
        ++s;
      }

      // Copy the string and replace backslashes with forward slashes along the
      // way.
      do {
        if (*s == NS_T('\\')) {
          *d = NS_T('/');
        } else {
          *d = *s;
        }
        ++s;
        ++d;
      } while (*s);
      *d = NS_T('\0');
      ++d;

      const size_t callbackBackupPathBufSize =
          sizeof(gCallbackBackupPath) / sizeof(gCallbackBackupPath[0]);
      const int callbackBackupPathLen =
          NS_tsnprintf(gCallbackBackupPath, callbackBackupPathBufSize,
                       NS_T("%s" CALLBACK_BACKUP_EXT), argv[callbackIndex]);

      if (callbackBackupPathLen < 0 ||
          callbackBackupPathLen >=
              static_cast<int>(callbackBackupPathBufSize)) {
        WriteStatusFile(USAGE_ERROR);
        LOG(("NS_main: callback backup path truncated"));
        output_finish();

        // Don't attempt to launch the callback when the callback path is
        // longer than expected.
        EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 1);
        return 1;
      }

      // Make a copy of the callback executable so it can be read when patching.
      if (!CopyFileW(argv[callbackIndex], gCallbackBackupPath, false)) {
        DWORD copyFileError = GetLastError();
        if (copyFileError == ERROR_ACCESS_DENIED) {
          WriteStatusFile(WRITE_ERROR_ACCESS_DENIED);
        } else {
          WriteStatusFile(WRITE_ERROR_CALLBACK_APP);
        }
        LOG(("NS_main: failed to copy callback file " LOG_S
             " into place at " LOG_S,
             argv[callbackIndex], gCallbackBackupPath));
        output_finish();
        EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 1);
        LaunchCallbackApp(argv[callbackIndex], argc - callbackIndex,
                          argv + callbackIndex, sUsingService);
        return 1;
      }

      // Since the process may be signaled as exited by WaitForSingleObject
      // before the release of the executable image try to lock the main
      // executable file multiple times before giving up.  If we end up giving
      // up, we won't fail the update.
      const int max_retries = 10;
      int retries = 1;
      DWORD lastWriteError = 0;
      do {
        // By opening a file handle wihout FILE_SHARE_READ to the callback
        // executable, the OS will prevent launching the process while it is
        // being updated.
        callbackFile = CreateFileW(targetPath, DELETE | GENERIC_WRITE,
                                   // allow delete, rename, and write
                                   FILE_SHARE_DELETE | FILE_SHARE_WRITE,
                                   nullptr, OPEN_EXISTING, 0, nullptr);
        if (callbackFile != INVALID_HANDLE_VALUE) {
          break;
        }

        lastWriteError = GetLastError();
        LOG(
            ("NS_main: callback app file open attempt %d failed. "
             "File: " LOG_S ". Last error: %d",
             retries, targetPath, lastWriteError));

        Sleep(100);
      } while (++retries <= max_retries);

      // CreateFileW will fail if the callback executable is already in use.
      if (callbackFile == INVALID_HANDLE_VALUE) {
        // Only fail the update if the last error was not a sharing violation.
        if (lastWriteError != ERROR_SHARING_VIOLATION) {
          LOG(
              ("NS_main: callback app file in use, failed to exclusively open "
               "executable file: " LOG_S,
               argv[callbackIndex]));
          if (lastWriteError == ERROR_ACCESS_DENIED) {
            WriteStatusFile(WRITE_ERROR_ACCESS_DENIED);
          } else {
            WriteStatusFile(WRITE_ERROR_CALLBACK_APP);
          }

          if (NS_tremove(gCallbackBackupPath) && errno != ENOENT) {
            LOG(
                ("NS_main: unable to remove backup of callback app file, "
                 "path: " LOG_S,
                 gCallbackBackupPath));
          }
          output_finish();
          EXIT_WHEN_ELEVATED(elevatedLockFilePath, updateLockFileHandle, 1);
          LaunchCallbackApp(argv[5], argc - callbackIndex, argv + callbackIndex,
                            sUsingService);
          return 1;
        }
        LOG(
            ("NS_main: callback app file in use, continuing without "
             "exclusive access for executable file: " LOG_S,
             argv[callbackIndex]));
      }
    }
  }

  // DELETE_DIR is not required when performing a staged update or replace
  // request; it can be used during a replace request but then it doesn't
  // use gDeleteDirPath.
  if (!sStagedUpdate && !sReplaceRequest) {
    // The directory to move files that are in use to on Windows. This directory
    // will be deleted after the update is finished, on OS reboot using
    // MoveFileEx if it contains files that are in use, or by the post update
    // process after the update finishes. On Windows when performing a normal
    // update (e.g. the update is not a staged update and is not a replace
    // request) gWorkingDirPath is the same as gInstallDirPath and
    // gWorkingDirPath is used because it is the destination directory.
    NS_tsnprintf(gDeleteDirPath,
                 sizeof(gDeleteDirPath) / sizeof(gDeleteDirPath[0]),
                 NS_T("%s/%s"), gWorkingDirPath, DELETE_DIR);

    if (NS_taccess(gDeleteDirPath, F_OK)) {
      NS_tmkdir(gDeleteDirPath, 0755);
    }
  }
#endif /* XP_WIN */

  // Run update process on a background thread. ShowProgressUI may return
  // before QuitProgressUI has been called, so wait for UpdateThreadFunc to
  // terminate. Avoid showing the progress UI when staging an update, or if this
  // is an elevated process on OSX.
  Thread t;
  if (t.Run(UpdateThreadFunc, nullptr) == 0) {
    if (!sStagedUpdate && !sReplaceRequest
#ifdef XP_MACOSX
        && !isElevated
#endif
    ) {
      ShowProgressUI();
    }
  }
  t.Join();

#ifdef XP_WIN
  if (argc > callbackIndex && !sReplaceRequest) {
    if (callbackFile != INVALID_HANDLE_VALUE) {
      CloseHandle(callbackFile);
    }
    // Remove the copy of the callback executable.
    if (NS_tremove(gCallbackBackupPath) && errno != ENOENT) {
      LOG(
          ("NS_main: non-fatal error removing backup of callback app file, "
           "path: " LOG_S,
           gCallbackBackupPath));
    }
  }

  if (!sStagedUpdate && !sReplaceRequest && _wrmdir(gDeleteDirPath)) {
    LOG(("NS_main: unable to remove directory: " LOG_S ", err: %d", DELETE_DIR,
         errno));
    // The directory probably couldn't be removed due to it containing files
    // that are in use and will be removed on OS reboot. The call to remove the
    // directory on OS reboot is done after the calls to remove the files so the
    // files are removed first on OS reboot since the directory must be empty
    // for the directory removal to be successful. The MoveFileEx call to remove
    // the directory on OS reboot will fail if the process doesn't have write
    // access to the HKEY_LOCAL_MACHINE registry key but this is ok since the
    // installer / uninstaller will delete the directory along with its contents
    // after an update is applied, on reinstall, and on uninstall.
    if (MoveFileEx(gDeleteDirPath, nullptr, MOVEFILE_DELAY_UNTIL_REBOOT)) {
      LOG(("NS_main: directory will be removed on OS reboot: " LOG_S,
           DELETE_DIR));
    } else {
      LOG(
          ("NS_main: failed to schedule OS reboot removal of "
           "directory: " LOG_S,
           DELETE_DIR));
    }
  }
#endif /* XP_WIN */

#ifdef XP_MACOSX
  if (isElevated) {
    SetGroupOwnershipAndPermissions(gInstallDirPath);
    freeArguments(argc, argv);
    CleanupElevatedMacUpdate(false);
  } else if (IsOwnedByGroupAdmin(gInstallDirPath)) {
    // If the group ownership of the Firefox .app bundle was set to the "admin"
    // group during a previous elevated update, we need to ensure that all files
    // in the bundle have group ownership of "admin" as well as write permission
    // for the group to not break updates in the future.
    SetGroupOwnershipAndPermissions(gInstallDirPath);
  }
#endif /* XP_MACOSX */

  output_finish();

  int retVal = LaunchCallbackAndPostProcessApps(argc, argv, callbackIndex
#ifdef XP_WIN
                                                ,
                                                elevatedLockFilePath,
                                                updateLockFileHandle
#elif XP_MACOSX
                                                  ,
                                                  isElevated
#endif
  );

  return retVal ? retVal : (gSucceeded ? 0 : 1);
}

class ActionList {
 public:
  ActionList() : mFirst(nullptr), mLast(nullptr), mCount(0) {}
  ~ActionList();

  void Append(Action* action);
  int Prepare();
  int Execute();
  void Finish(int status);

 private:
  Action* mFirst;
  Action* mLast;
  int mCount;
};

ActionList::~ActionList() {
  Action* a = mFirst;
  while (a) {
    Action* b = a;
    a = a->mNext;
    delete b;
  }
}

void ActionList::Append(Action* action) {
  if (mLast) {
    mLast->mNext = action;
  } else {
    mFirst = action;
  }

  mLast = action;
  mCount++;
}

int ActionList::Prepare() {
  // If the action list is empty then we should fail in order to signal that
  // something has gone wrong. Otherwise we report success when nothing is
  // actually done. See bug 327140.
  if (mCount == 0) {
    LOG(("empty action list"));
    return MAR_ERROR_EMPTY_ACTION_LIST;
  }

  Action* a = mFirst;
  int i = 0;
  while (a) {
    int rv = a->Prepare();
    if (rv) {
      return rv;
    }

    float percent = float(++i) / float(mCount);
    UpdateProgressUI(PROGRESS_PREPARE_SIZE * percent);

    a = a->mNext;
  }

  return OK;
}

int ActionList::Execute() {
  int currentProgress = 0, maxProgress = 0;
  Action* a = mFirst;
  while (a) {
    maxProgress += a->mProgressCost;
    a = a->mNext;
  }

  a = mFirst;
  while (a) {
    int rv = a->Execute();
    if (rv) {
      LOG(("### execution failed"));
      return rv;
    }

    currentProgress += a->mProgressCost;
    float percent = float(currentProgress) / float(maxProgress);
    UpdateProgressUI(PROGRESS_PREPARE_SIZE + PROGRESS_EXECUTE_SIZE * percent);

    a = a->mNext;
  }

  return OK;
}

void ActionList::Finish(int status) {
  Action* a = mFirst;
  int i = 0;
  while (a) {
    a->Finish(status);

    float percent = float(++i) / float(mCount);
    UpdateProgressUI(PROGRESS_PREPARE_SIZE + PROGRESS_EXECUTE_SIZE +
                     PROGRESS_FINISH_SIZE * percent);

    a = a->mNext;
  }

  if (status == OK) {
    gSucceeded = true;
  }
}

#ifdef XP_WIN
int add_dir_entries(const NS_tchar* dirpath, ActionList* list) {
  int rv = OK;
  WIN32_FIND_DATAW finddata;
  HANDLE hFindFile;
  NS_tchar searchspec[MAXPATHLEN];
  NS_tchar foundpath[MAXPATHLEN];

  NS_tsnprintf(searchspec, sizeof(searchspec) / sizeof(searchspec[0]),
               NS_T("%s*"), dirpath);
  mozilla::UniquePtr<const NS_tchar> pszSpec(get_full_path(searchspec));

  hFindFile = FindFirstFileW(pszSpec.get(), &finddata);
  if (hFindFile != INVALID_HANDLE_VALUE) {
    do {
      // Don't process the current or parent directory.
      if (NS_tstrcmp(finddata.cFileName, NS_T(".")) == 0 ||
          NS_tstrcmp(finddata.cFileName, NS_T("..")) == 0) {
        continue;
      }

      NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                   NS_T("%s%s"), dirpath, finddata.cFileName);
      if (finddata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
        NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                     NS_T("%s/"), foundpath);
        // Recurse into the directory.
        rv = add_dir_entries(foundpath, list);
        if (rv) {
          LOG(("add_dir_entries error: " LOG_S ", err: %d", foundpath, rv));
          return rv;
        }
      } else {
        // Add the file to be removed to the ActionList.
        NS_tchar* quotedpath = get_quoted_path(foundpath);
        if (!quotedpath) {
          return PARSE_ERROR;
        }

        mozilla::UniquePtr<Action> action(new RemoveFile());
        rv = action->Parse(quotedpath);
        if (rv) {
          LOG(("add_dir_entries Parse error on recurse: " LOG_S ", err: %d",
               quotedpath, rv));
          free(quotedpath);
          return rv;
        }
        free(quotedpath);

        list->Append(action.release());
      }
    } while (FindNextFileW(hFindFile, &finddata) != 0);

    FindClose(hFindFile);
    {
      // Add the directory to be removed to the ActionList.
      NS_tchar* quotedpath = get_quoted_path(dirpath);
      if (!quotedpath) {
        return PARSE_ERROR;
      }

      mozilla::UniquePtr<Action> action(new RemoveDir());
      rv = action->Parse(quotedpath);
      if (rv) {
        LOG(("add_dir_entries Parse error on close: " LOG_S ", err: %d",
             quotedpath, rv));
      } else {
        list->Append(action.release());
      }
      free(quotedpath);
    }
  }

  return rv;
}

#elif defined(HAVE_FTS_H)
  int add_dir_entries(const NS_tchar* dirpath, ActionList* list) {
    int rv = OK;
    FTS* ftsdir;
    FTSENT* ftsdirEntry;
    mozilla::UniquePtr<NS_tchar[]> searchpath(get_full_path(dirpath));

    // Remove the trailing slash so the paths don't contain double slashes. The
    // existence of the slash has already been checked in DoUpdate.
    searchpath[NS_tstrlen(searchpath.get()) - 1] = NS_T('\0');
    char* const pathargv[] = {searchpath.get(), nullptr};

    // FTS_NOCHDIR is used so relative paths from the destination directory are
    // returned.
    if (!(ftsdir = fts_open(pathargv,
                            FTS_PHYSICAL | FTS_NOSTAT | FTS_XDEV | FTS_NOCHDIR,
                            nullptr))) {
      return UNEXPECTED_FILE_OPERATION_ERROR;
    }

    while ((ftsdirEntry = fts_read(ftsdir)) != nullptr) {
      NS_tchar foundpath[MAXPATHLEN];
      NS_tchar* quotedpath = nullptr;
      mozilla::UniquePtr<Action> action;

      switch (ftsdirEntry->fts_info) {
        // Filesystem objects that shouldn't be in the application's directories
        case FTS_SL:
        case FTS_SLNONE:
        case FTS_DEFAULT:
          LOG(("add_dir_entries: found a non-standard file: " LOG_S,
               ftsdirEntry->fts_path));
          // Fall through and try to remove as a file
          [[fallthrough]];

        // Files
        case FTS_F:
        case FTS_NSOK:
          // Add the file to be removed to the ActionList.
          NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                       NS_T("%s"), ftsdirEntry->fts_accpath);
          quotedpath = get_quoted_path(get_relative_path(foundpath));
          if (!quotedpath) {
            rv = UPDATER_QUOTED_PATH_MEM_ERROR;
            break;
          }
          action.reset(new RemoveFile());
          rv = action->Parse(quotedpath);
          free(quotedpath);
          if (!rv) {
            list->Append(action.release());
          }
          break;

        // Directories
        case FTS_DP:
          // Add the directory to be removed to the ActionList.
          NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                       NS_T("%s/"), ftsdirEntry->fts_accpath);
          quotedpath = get_quoted_path(get_relative_path(foundpath));
          if (!quotedpath) {
            rv = UPDATER_QUOTED_PATH_MEM_ERROR;
            break;
          }

          action.reset(new RemoveDir());
          rv = action->Parse(quotedpath);
          free(quotedpath);
          if (!rv) {
            list->Append(action.release());
          }
          break;

        // Errors
        case FTS_DNR:
        case FTS_NS:
          // ENOENT is an acceptable error for FTS_DNR and FTS_NS and means that
          // we're racing with ourselves. Though strange, the entry will be
          // removed anyway.
          if (ENOENT == ftsdirEntry->fts_errno) {
            rv = OK;
            break;
          }
          [[fallthrough]];

        case FTS_ERR:
          rv = UNEXPECTED_FILE_OPERATION_ERROR;
          LOG(("add_dir_entries: fts_read() error: " LOG_S ", err: %d",
               ftsdirEntry->fts_path, ftsdirEntry->fts_errno));
          break;

        case FTS_DC:
          rv = UNEXPECTED_FILE_OPERATION_ERROR;
          LOG(("add_dir_entries: fts_read() returned FT_DC: " LOG_S,
               ftsdirEntry->fts_path));
          break;

        default:
          // FTS_D is ignored and FTS_DP is used instead (post-order).
          rv = OK;
          break;
      }

      if (rv != OK) {
        break;
      }
    }

    fts_close(ftsdir);

    return rv;
  }

#else

int add_dir_entries(const NS_tchar* dirpath, ActionList* list) {
  int rv = OK;
  NS_tchar foundpath[PATH_MAX];
  struct {
    dirent dent_buffer;
    char chars[NAME_MAX];
  } ent_buf;
  struct dirent* ent;
  mozilla::UniquePtr<NS_tchar[]> searchpath(get_full_path(dirpath));

  DIR* dir = opendir(searchpath.get());
  if (!dir) {
    LOG(("add_dir_entries error on opendir: " LOG_S ", err: %d",
         searchpath.get(), errno));
    return UNEXPECTED_FILE_OPERATION_ERROR;
  }

  while (readdir_r(dir, (dirent*)&ent_buf, &ent) == 0 && ent) {
    if ((strcmp(ent->d_name, ".") == 0) || (strcmp(ent->d_name, "..") == 0)) {
      continue;
    }

    NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                 NS_T("%s%s"), searchpath.get(), ent->d_name);
    struct stat64 st_buf;
    int test = stat64(foundpath, &st_buf);
    if (test) {
      closedir(dir);
      return UNEXPECTED_FILE_OPERATION_ERROR;
    }
    if (S_ISDIR(st_buf.st_mode)) {
      NS_tsnprintf(foundpath, sizeof(foundpath) / sizeof(foundpath[0]),
                   NS_T("%s%s/"), dirpath, ent->d_name);
      // Recurse into the directory.
      rv = add_dir_entries(foundpath, list);
      if (rv) {
        LOG(("add_dir_entries error: " LOG_S ", err: %d", foundpath, rv));
        closedir(dir);
        return rv;
      }
    } else {
      // Add the file to be removed to the ActionList.
      NS_tchar* quotedpath = get_quoted_path(get_relative_path(foundpath));
      if (!quotedpath) {
        closedir(dir);
        return PARSE_ERROR;
      }

      mozilla::UniquePtr<Action> action(new RemoveFile());
      rv = action->Parse(quotedpath);
      if (rv) {
        LOG(("add_dir_entries Parse error on recurse: " LOG_S ", err: %d",
             quotedpath, rv));
        free(quotedpath);
        closedir(dir);
        return rv;
      }
      free(quotedpath);

      list->Append(action.release());
    }
  }
  closedir(dir);

  // Add the directory to be removed to the ActionList.
  NS_tchar* quotedpath = get_quoted_path(get_relative_path(dirpath));
  if (!quotedpath) {
    return PARSE_ERROR;
  }

  mozilla::UniquePtr<Action> action(new RemoveDir());
  rv = action->Parse(quotedpath);
  if (rv) {
    LOG(("add_dir_entries Parse error on close: " LOG_S ", err: %d", quotedpath,
         rv));
  } else {
    list->Append(action.release());
  }
  free(quotedpath);

  return rv;
}

#endif

/*
 * Gets the contents of an update manifest file. The return value is malloc'd
 * and it is the responsibility of the caller to free it.
 *
 * @param  manifest
 *         The full path to the manifest file.
 * @return On success the contents of the manifest and nullptr otherwise.
 */
static NS_tchar* GetManifestContents(const NS_tchar* manifest) {
  AutoFile mfile(NS_tfopen(manifest, NS_T("rb")));
  if (mfile == nullptr) {
    LOG(("GetManifestContents: error opening manifest file: " LOG_S, manifest));
    return nullptr;
  }

  struct stat ms;
  int rv = fstat(fileno((FILE*)mfile), &ms);
  if (rv) {
    LOG(("GetManifestContents: error stating manifest file: " LOG_S, manifest));
    return nullptr;
  }

  char* mbuf = (char*)malloc(ms.st_size + 1);
  if (!mbuf) {
    return nullptr;
  }

  size_t r = ms.st_size;
  char* rb = mbuf;
  while (r) {
    const size_t count = mmin(SSIZE_MAX, r);
    size_t c = fread(rb, 1, count, mfile);
    if (c != count) {
      LOG(("GetManifestContents: error reading manifest file: " LOG_S,
           manifest));
      free(mbuf);
      return nullptr;
    }

    r -= c;
    rb += c;
  }
  *rb = '\0';

#ifndef XP_WIN
  return mbuf;
#else
    NS_tchar* wrb = (NS_tchar*)malloc((ms.st_size + 1) * sizeof(NS_tchar));
    if (!wrb) {
      free(mbuf);
      return nullptr;
    }

    if (!MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, mbuf, -1, wrb,
                             ms.st_size + 1)) {
      LOG(("GetManifestContents: error converting utf8 to utf16le: %d",
           GetLastError()));
      free(mbuf);
      free(wrb);
      return nullptr;
    }
    free(mbuf);

    return wrb;
#endif
}

int AddPreCompleteActions(ActionList* list) {
#ifdef XP_MACOSX
  mozilla::UniquePtr<NS_tchar[]> manifestPath(
      get_full_path(NS_T("Contents/Resources/precomplete")));
#else
    mozilla::UniquePtr<NS_tchar[]> manifestPath(
        get_full_path(NS_T("precomplete")));
#endif

  NS_tchar* buf = GetManifestContents(manifestPath.get());
  if (!buf) {
    LOG(
        ("AddPreCompleteActions: error getting contents of precomplete "
         "manifest"));
    // Applications aren't required to have a precomplete manifest. The mar
    // generation scripts enforce the presence of a precomplete manifest.
    return OK;
  }
  NS_tchar* rb = buf;

  int rv;
  NS_tchar* line;
  while ((line = mstrtok(kNL, &rb)) != 0) {
    // skip comments
    if (*line == NS_T('#')) {
      continue;
    }

    NS_tchar* token = mstrtok(kWhitespace, &line);
    if (!token) {
      LOG(("AddPreCompleteActions: token not found in manifest"));
      free(buf);
      return PARSE_ERROR;
    }

    Action* action = nullptr;
    if (NS_tstrcmp(token, NS_T("remove")) == 0) {  // rm file
      action = new RemoveFile();
    } else if (NS_tstrcmp(token, NS_T("remove-cc")) ==
               0) {  // no longer supported
      continue;
    } else if (NS_tstrcmp(token, NS_T("rmdir")) == 0) {  // rmdir if  empty
      action = new RemoveDir();
    } else {
      LOG(("AddPreCompleteActions: unknown token: " LOG_S, token));
      free(buf);
      return PARSE_ERROR;
    }

    if (!action) {
      free(buf);
      return BAD_ACTION_ERROR;
    }

    rv = action->Parse(line);
    if (rv) {
      delete action;
      free(buf);
      return rv;
    }

    list->Append(action);
  }

  free(buf);
  return OK;
}

int DoUpdate() {
  NS_tchar manifest[MAXPATHLEN];
  NS_tsnprintf(manifest, sizeof(manifest) / sizeof(manifest[0]),
               NS_T("%s/updating/update.manifest"), gWorkingDirPath);
  ensure_parent_dir(manifest);

  // extract the manifest
  int rv = gArchiveReader.ExtractFile("updatev3.manifest", manifest);
  if (rv) {
    LOG(("DoUpdate: error extracting manifest file"));
    return rv;
  }

  NS_tchar* buf = GetManifestContents(manifest);
  // The manifest is located in the <working_dir>/updating directory which is
  // removed after the update has finished so don't delete it here.
  if (!buf) {
    LOG(("DoUpdate: error opening manifest file: " LOG_S, manifest));
    return READ_ERROR;
  }
  NS_tchar* rb = buf;

  ActionList list;
  NS_tchar* line;
  bool isFirstAction = true;
  while ((line = mstrtok(kNL, &rb)) != 0) {
    // skip comments
    if (*line == NS_T('#')) {
      continue;
    }

    NS_tchar* token = mstrtok(kWhitespace, &line);
    if (!token) {
      LOG(("DoUpdate: token not found in manifest"));
      free(buf);
      return PARSE_ERROR;
    }

    if (isFirstAction) {
      isFirstAction = false;
      // The update manifest isn't required to have a type declaration. The mar
      // generation scripts enforce the presence of the type declaration.
      if (NS_tstrcmp(token, NS_T("type")) == 0) {
        const NS_tchar* type = mstrtok(kQuote, &line);
        LOG(("UPDATE TYPE " LOG_S, type));
        if (NS_tstrcmp(type, NS_T("complete")) == 0) {
          rv = AddPreCompleteActions(&list);
          if (rv) {
            free(buf);
            return rv;
          }
        }
        continue;
      }
    }

    Action* action = nullptr;
    if (NS_tstrcmp(token, NS_T("remove")) == 0) {  // rm file
      action = new RemoveFile();
    } else if (NS_tstrcmp(token, NS_T("rmdir")) == 0) {  // rmdir if empty
      action = new RemoveDir();
    } else if (NS_tstrcmp(token, NS_T("rmrfdir")) == 0) {  // rmdir recursive
      const NS_tchar* reldirpath = mstrtok(kQuote, &line);
      if (!reldirpath) {
        free(buf);
        return PARSE_ERROR;
      }

      if (reldirpath[NS_tstrlen(reldirpath) - 1] != NS_T('/')) {
        free(buf);
        return PARSE_ERROR;
      }

      rv = add_dir_entries(reldirpath, &list);
      if (rv) {
        free(buf);
        return rv;
      }

      continue;
    } else if (NS_tstrcmp(token, NS_T("add")) == 0) {
      action = new AddFile();
    } else if (NS_tstrcmp(token, NS_T("patch")) == 0) {
      action = new PatchFile();
    } else if (NS_tstrcmp(token, NS_T("add-if")) == 0) {  // Add if exists
      action = new AddIfFile();
    } else if (NS_tstrcmp(token, NS_T("add-if-not")) ==
               0) {  // Add if not exists
      action = new AddIfNotFile();
    } else if (NS_tstrcmp(token, NS_T("patch-if")) == 0) {  // Patch if exists
      action = new PatchIfFile();
    } else {
      LOG(("DoUpdate: unknown token: " LOG_S, token));
      free(buf);
      return PARSE_ERROR;
    }

    if (!action) {
      free(buf);
      return BAD_ACTION_ERROR;
    }

    rv = action->Parse(line);
    if (rv) {
      free(buf);
      return rv;
    }

    list.Append(action);
  }

  rv = list.Prepare();
  if (rv) {
    free(buf);
    return rv;
  }

  rv = list.Execute();

  list.Finish(rv);
  free(buf);
  return rv;
}