# 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/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

package Bugzilla::Install::Filesystem;

# NOTE: This package may "use" any modules that it likes,
# and localconfig is available. However, all functions in this
# package should assume that:
#
# * Templates are not available.
# * Files do not have the correct permissions.
# * The database does not exist.

use 5.10.1;
use strict;
use warnings;

use Bugzilla::Constants;
use Bugzilla::Error;
use Bugzilla::Install::Localconfig;
use Bugzilla::Install::Util qw(install_string);
use Bugzilla::Util;
use Bugzilla::Hook;

use File::Find;
use File::Path;
use File::Basename;
use File::Copy qw(move);
use File::Spec;
use IO::File;
use POSIX ();

use parent qw(Exporter);
our @EXPORT = qw(
  update_filesystem
  create_htaccess
  fix_all_file_permissions
  fix_dir_permissions
  fix_file_permissions
);

use constant HT_DEFAULT_DENY => <<EOT;
# nothing in this directory is retrievable unless overridden by an .htaccess
# in a subdirectory
<IfModule mod_version.c>
  <IfVersion < 2.4>
    Deny from all
  </IfVersion>
  <IfVersion >= 2.4>
    Require all denied
  </IfVersion>
</IfModule>
<IfModule !mod_version.c>
  Deny from all
</IfModule>
EOT

###############
# Permissions #
###############

# Used by the permissions "constants" below.
sub _suexec { Bugzilla->localconfig->{'use_suexec'} }
sub _group  { Bugzilla->localconfig->{'webservergroup'} }

# Writeable by the owner only.
use constant OWNER_WRITE => 0600;

# Executable by the owner only.
use constant OWNER_EXECUTE => 0700;

# A directory which is only writeable by the owner.
use constant DIR_OWNER_WRITE => 0700;

# A cgi script that the webserver can execute.
sub WS_EXECUTE { _group() ? 0750 : 0755 }

# A file that is read by cgi scripts, but is not ever read
# directly by the webserver.
sub CGI_READ { _group() ? 0640 : 0644 }

# A file that is written to by cgi scripts, but is not ever
# read or written directly by the webserver.
sub CGI_WRITE { _group() ? 0660 : 0666 }

# A file that is served directly by the web server.
sub WS_SERVE { (_group() and !_suexec()) ? 0640 : 0644 }

# A directory whose contents can be read or served by the
# webserver (so even directories containing cgi scripts
# would have this permission).
sub DIR_WS_SERVE { (_group() and !_suexec()) ? 0750 : 0755 }

# A directory that is read by cgi scripts, but is never accessed
# directly by the webserver
sub DIR_CGI_READ { _group() ? 0750 : 0755 }

# A directory that is written to by cgi scripts, but where the
# scripts never needs to overwrite files created by other
# users.
sub DIR_CGI_WRITE { _group() ? 0770 : 01777 }

# A directory that is written to by cgi scripts, where the
# scripts need to overwrite files created by other users.
sub DIR_CGI_OVERWRITE { _group() ? 0770 : 0777 }

# This can be combined (using "|") with other permissions for
# directories that, in addition to their normal permissions (such
# as DIR_CGI_WRITE) also have content served directly from them
# (or their subdirectories) to the user, via the webserver.
sub DIR_ALSO_WS_SERVE { _suexec() ? 0001 : 0 }

# This looks like a constant because it effectively is, but
# it has to call other subroutines and read the current filesystem,
# so it's defined as a sub. This is not exported, so it doesn't have
# a perldoc. However, look at the various hashes defined inside this
# function to understand what it returns. (There are comments throughout.)
#
# The rationale for the file permissions is that there is a group the
# web server executes the scripts as, so the cgi scripts should not be writable
# by this group. Otherwise someone may find it possible to change the cgis
# when exploiting some security flaw somewhere (not necessarily in Bugzilla!)
sub FILESYSTEM {
  my $datadir        = bz_locations()->{'datadir'};
  my $attachdir      = bz_locations()->{'attachdir'};
  my $extensionsdir  = bz_locations()->{'extensionsdir'};
  my $webdotdir      = bz_locations()->{'webdotdir'};
  my $templatedir    = bz_locations()->{'templatedir'};
  my $libdir         = bz_locations()->{'libpath'};
  my $extlib         = bz_locations()->{'ext_libpath'};
  my $skinsdir       = bz_locations()->{'skinsdir'};
  my $localconfig    = bz_locations()->{'localconfig'};
  my $template_cache = bz_locations()->{'template_cache'};
  my $graphsdir      = bz_locations()->{'graphsdir'};
  my $assetsdir      = bz_locations()->{'assetsdir'};

  # We want to set the permissions the same for all localconfig files
  # across all PROJECTs, so we do something special with $localconfig,
  # lower down in the permissions section.
  if ($ENV{PROJECT}) {
    $localconfig =~ s/\.\Q$ENV{PROJECT}\E$//;
  }

  # Note: When being processed by checksetup, these have their permissions
  # set in this order: %all_dirs, %recurse_dirs, %all_files.
  #
  # Each is processed in alphabetical order of keys, so shorter keys
  # will have their permissions set before longer keys (thus setting
  # the permissions on parent directories before setting permissions
  # on their children).

  # --- FILE PERMISSIONS (Non-created files) --- #
  my %files = (
    '*' => {perms => OWNER_WRITE},

    # Some .pl files are WS_EXECUTE because we want
    # users to be able to cron them or otherwise run
    # them as a secure user, like the webserver owner.
    '*.cgi'                        => {perms => WS_EXECUTE},
    'whineatnews.pl'               => {perms => WS_EXECUTE},
    'collectstats.pl'              => {perms => WS_EXECUTE},
    'importxml.pl'                 => {perms => WS_EXECUTE},
    'testserver.pl'                => {perms => WS_EXECUTE},
    'whine.pl'                     => {perms => WS_EXECUTE},
    'email_in.pl'                  => {perms => WS_EXECUTE},
    'sanitycheck.pl'               => {perms => WS_EXECUTE},
    'checksetup.pl'                => {perms => OWNER_EXECUTE},
    'runtests.pl'                  => {perms => OWNER_EXECUTE},
    'jobqueue.pl'                  => {perms => OWNER_EXECUTE},
    'migrate.pl'                   => {perms => OWNER_EXECUTE},
    'install-module.pl'            => {perms => OWNER_EXECUTE},
    'clean-bug-user-last-visit.pl' => {perms => WS_EXECUTE},

    'Bugzilla.pm'   => {perms => CGI_READ},
    "$localconfig*" => {perms => CGI_READ},
    'bugzilla.dtd'  => {perms => WS_SERVE},
    'mod_perl.pl'   => {perms => WS_SERVE},
    'robots.txt'    => {perms => WS_SERVE},
    '.htaccess'     => {perms => WS_SERVE},

    'contrib/README'           => {perms => OWNER_WRITE},
    'contrib/*/README'         => {perms => OWNER_WRITE},
    'contrib/Bugzilla.pm'      => {perms => OWNER_WRITE},
    'docs/bugzilla.ent'        => {perms => OWNER_WRITE},
    'docs/makedocs.pl'         => {perms => OWNER_EXECUTE},
    'docs/style.css'           => {perms => WS_SERVE},
    'docs/*/rel_notes.txt'     => {perms => WS_SERVE},
    'docs/*/README.docs'       => {perms => OWNER_WRITE},
    "$datadir/params.json"     => {perms => CGI_WRITE},
    "$datadir/old-params.txt"  => {perms => OWNER_WRITE},
    "$extensionsdir/create.pl" => {perms => OWNER_EXECUTE},
    "$extensionsdir/*/*.pl"    => {perms => WS_EXECUTE},
  );

  # Directories that we want to set the perms on, but not
  # recurse through. These are directories we didn't create
  # in checkesetup.pl.
  my %non_recurse_dirs = ('.' => DIR_WS_SERVE, docs => DIR_WS_SERVE,);

  # This sets the permissions for each item inside each of these
  # directories, including the directory itself.
  # 'CVS' directories are special, though, and are never readable by
  # the webserver.
  my %recurse_dirs = (

    # Writeable directories
    $template_cache => {files => CGI_READ,  dirs => DIR_CGI_OVERWRITE},
    $attachdir      => {files => CGI_WRITE, dirs => DIR_CGI_WRITE},
    $webdotdir => {files => WS_SERVE, dirs => DIR_CGI_WRITE | DIR_ALSO_WS_SERVE},
    $graphsdir => {files => WS_SERVE, dirs => DIR_CGI_WRITE | DIR_ALSO_WS_SERVE},
    "$datadir/db" => {files => CGI_WRITE, dirs => DIR_CGI_WRITE},
    $assetsdir =>
      {files => WS_SERVE, dirs => DIR_CGI_OVERWRITE | DIR_ALSO_WS_SERVE},

    # Readable directories
    "$datadir/mining"  => {files => CGI_READ, dirs => DIR_CGI_READ},
    "$libdir/Bugzilla" => {files => CGI_READ, dirs => DIR_CGI_READ},
    $extlib            => {files => CGI_READ, dirs => DIR_CGI_READ},
    $templatedir       => {files => CGI_READ, dirs => DIR_CGI_READ},

    # Directories in the extensions/ dir are WS_SERVE so that
    # the web/ directories can be served by the web server.
    # But, for extra security, we deny direct webserver access to
    # the lib/ and template/ directories of extensions.
    $extensionsdir              => {files => CGI_READ, dirs => DIR_WS_SERVE},
    "$extensionsdir/*/lib"      => {files => CGI_READ, dirs => DIR_CGI_READ},
    "$extensionsdir/*/template" => {files => CGI_READ, dirs => DIR_CGI_READ},

    # Content served directly by the webserver
    images                 => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    js                     => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    $skinsdir              => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    'docs/*/html'          => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    'docs/*/pdf'           => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    'docs/*/txt'           => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    'docs/*/images'        => {files => WS_SERVE, dirs => DIR_WS_SERVE},
    "$extensionsdir/*/web" => {files => WS_SERVE, dirs => DIR_WS_SERVE},

    # Directories only for the owner, not for the webserver.
    '.bzr'       => {files => OWNER_WRITE,   dirs => DIR_OWNER_WRITE},
    t            => {files => OWNER_WRITE,   dirs => DIR_OWNER_WRITE},
    xt           => {files => OWNER_WRITE,   dirs => DIR_OWNER_WRITE},
    'docs/lib'   => {files => OWNER_WRITE,   dirs => DIR_OWNER_WRITE},
    'docs/*/xml' => {files => OWNER_WRITE,   dirs => DIR_OWNER_WRITE},
    'contrib'    => {files => OWNER_EXECUTE, dirs => DIR_OWNER_WRITE,},
  );

  # --- FILES TO CREATE --- #

  # The name of each directory that we should actually *create*,
  # pointing at its default permissions.
  my %create_dirs = (

    # This is DIR_ALSO_WS_SERVE because it contains $webdotdir and
    # $assetsdir.
    $datadir => DIR_CGI_OVERWRITE | DIR_ALSO_WS_SERVE,

    # Directories that are read-only for cgi scripts
    "$datadir/mining"     => DIR_CGI_READ,
    "$datadir/extensions" => DIR_CGI_READ,
    $extensionsdir        => DIR_CGI_READ,

    # Directories that cgi scripts can write to.
    "$datadir/db" => DIR_CGI_WRITE,
    $attachdir    => DIR_CGI_WRITE,
    $graphsdir    => DIR_CGI_WRITE | DIR_ALSO_WS_SERVE,
    $webdotdir    => DIR_CGI_WRITE | DIR_ALSO_WS_SERVE,
    $assetsdir    => DIR_CGI_WRITE | DIR_ALSO_WS_SERVE,

    # Directories that contain content served directly by the web server.
    "$skinsdir/custom"  => DIR_WS_SERVE,
    "$skinsdir/contrib" => DIR_WS_SERVE,
  );

  # The name of each file, pointing at its default permissions and
  # default contents.
  my %create_files = (
    "$datadir/extensions/additional" => {perms => CGI_READ, contents => ''},

    # We create this file so that it always has the right owner
    # and permissions. Otherwise, the webserver creates it as
    # owned by itself, which can cause problems if jobqueue.pl
    # or something else is not running as the webserver or root.
    "$datadir/mailer.testfile" => {perms => CGI_WRITE, contents => ''},
  );

  # Because checksetup controls the creation of index.html separately
  # from all other files, it gets its very own hash.
  my %index_html = (
    'index.html' => {
      perms    => WS_SERVE,
      contents => <<EOT
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta http-equiv="Refresh" content="0; URL=index.cgi">
</head>
<body>
  <h1>I think you are looking for <a href="index.cgi">index.cgi</a></h1>
</body>
</html>
EOT
    }
  );

  # Because checksetup controls the .htaccess creation separately
  # by a localconfig variable, these go in a separate variable from
  # %create_files.
  #
  # Note that these get WS_SERVE as their permission
  # because they're *read* by the webserver, even though they're not
  # actually, themselves, served.
  my %htaccess = (
    "$attachdir/.htaccess" => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    "$libdir/Bugzilla/.htaccess" =>
      {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    "$extlib/.htaccess"      => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    "$templatedir/.htaccess" => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    'contrib/.htaccess'      => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    't/.htaccess'            => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    'xt/.htaccess'           => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},
    "$datadir/.htaccess"     => {perms => WS_SERVE, contents => HT_DEFAULT_DENY},

    "$graphsdir/.htaccess" => {
      perms    => WS_SERVE,
      contents => <<EOT
# Allow access to .png and .gif files.
<FilesMatch (\\.gif|\\.png)\$>
  <IfModule mod_version.c>
    <IfVersion < 2.4>
      Allow from all
    </IfVersion>
    <IfVersion >= 2.4>
      Require all granted
    </IfVersion>
  </IfModule>
  <IfModule !mod_version.c>
    Allow from all
  </IfModule>
</FilesMatch>

# And no directory listings, either.
<IfModule mod_version.c>
  <IfVersion < 2.4>
    Deny from all
  </IfVersion>
  <IfVersion >= 2.4>
    Require all denied
  </IfVersion>
</IfModule>
<IfModule !mod_version.c>
  Deny from all
</IfModule>
EOT
    },

    "$webdotdir/.htaccess" => {
      perms    => WS_SERVE,
      contents => <<EOT
# Restrict access to .dot files to the public webdot server at research.att.com
# if research.att.com ever changes their IP, or if you use a different
# webdot server, you'll need to edit this
<FilesMatch \\.dot\$>
  <IfModule mod_version.c>
    <IfVersion < 2.4>
      Allow from 192.20.225.0/24
      Deny from all
    </IfVersion>
    <IfVersion >= 2.4>
      Require ip 192.20.225.0/24
      Require all denied
    </IfVersion>
  </IfModule>
  <IfModule !mod_version.c>
    Allow from 192.20.225.0/24
    Deny from all
  </IfModule>
</FilesMatch>

 # Allow access to .png files created by a local copy of 'dot'
 <FilesMatch \\.png\$>
  <IfModule mod_version.c>
    <IfVersion < 2.4>
      Allow from all
    </IfVersion>
    <IfVersion >= 2.4>
      Require all granted
    </IfVersion>
  </IfModule>
  <IfModule !mod_version.c>
    Allow from all
  </IfModule>
</FilesMatch>

# And no directory listings, either.
<IfModule mod_version.c>
  <IfVersion < 2.4>
    Deny from all
  </IfVersion>
  <IfVersion >= 2.4>
    Require all denied
  </IfVersion>
</IfModule>
<IfModule !mod_version.c>
  Deny from all
</IfModule>
EOT
    },

    "$assetsdir/.htaccess" => {
      perms    => WS_SERVE,
      contents => <<EOT
# Allow access to .css files
<FilesMatch \\.(css|js)\$>
  <IfModule mod_version.c>
    <IfVersion < 2.4>
      Allow from all
    </IfVersion>
    <IfVersion >= 2.4>
      Require all granted
    </IfVersion>
  </IfModule>
  <IfModule !mod_version.c>
     Allow from all
  </IfModule>
</FilesMatch>

# And no directory listings, either.
<IfModule mod_version.c>
  <IfVersion < 2.4>
    Deny from all
  </IfVersion>
  <IfVersion >= 2.4>
    Require all denied
  </IfVersion>
</IfModule>
<IfModule !mod_version.c>
  Deny from all
</IfModule>
EOT
    },

  );

  Bugzilla::Hook::process(
    'install_filesystem',
    {
      files            => \%files,
      create_dirs      => \%create_dirs,
      non_recurse_dirs => \%non_recurse_dirs,
      recurse_dirs     => \%recurse_dirs,
      create_files     => \%create_files,
      htaccess         => \%htaccess,
    }
  );

  my %all_files = (%create_files, %htaccess, %index_html, %files);
  my %all_dirs  = (%create_dirs,  %non_recurse_dirs);

  return {
    create_dirs  => \%create_dirs,
    recurse_dirs => \%recurse_dirs,
    all_dirs     => \%all_dirs,

    create_files => \%create_files,
    htaccess     => \%htaccess,
    index_html   => \%index_html,
    all_files    => \%all_files,
  };
}

sub update_filesystem {
  my ($params) = @_;
  my $fs       = FILESYSTEM();
  my %dirs     = %{$fs->{create_dirs}};
  my %files    = %{$fs->{create_files}};

  my $datadir   = bz_locations->{'datadir'};
  my $graphsdir = bz_locations->{'graphsdir'};
  my $assetsdir = bz_locations->{'assetsdir'};

  # If the graphs/ directory doesn't exist, we're upgrading from
  # a version old enough that we need to update the $datadir/mining
  # format.
  if (-d "$datadir/mining" && !-d $graphsdir) {
    _update_old_charts($datadir);
  }

  # If there is a file named '-All-' in $datadir/mining, then we're still
  # having mining files named by product name, and we need to convert them to
  # files named by product ID.
  if (-e File::Spec->catfile($datadir, 'mining', '-All-')) {
    _update_old_mining_filenames(File::Spec->catdir($datadir, 'mining'));
  }

  # By sorting the dirs, we assure that shorter-named directories
  # (meaning parent directories) are always created before their
  # child directories.
  foreach my $dir (sort keys %dirs) {
    unless (-d $dir) {
      print "Creating $dir directory...\n";
      mkdir $dir or die "mkdir $dir failed: $!";

      # For some reason, passing in the permissions to "mkdir"
      # doesn't work right, but doing a "chmod" does.
      chmod $dirs{$dir}, $dir or warn "Cannot chmod $dir: $!";
    }
  }

  # Move the testfile if we can't write to it, so that we can re-create
  # it with the correct permissions below.
  my $testfile = "$datadir/mailer.testfile";
  if (-e $testfile and !-w $testfile) {
    _rename_file($testfile, "$testfile.old");
  }

  # If old-params.txt exists in the root directory, move it to datadir.
  my $oldparamsfile = "old_params.txt";
  if (-e $oldparamsfile) {
    _rename_file($oldparamsfile, "$datadir/$oldparamsfile");
  }

  # Remove old assets htaccess file to force recreation with correct values.
  if (-e "$assetsdir/.htaccess") {
    if (read_text("$assetsdir/.htaccess") =~ /<FilesMatch \\\.css\$>/) {
      unlink("$assetsdir/.htaccess");
    }
  }

  _create_files(%files);
  if ($params->{index_html}) {
    _create_files(%{$fs->{index_html}});
  }
  elsif (-e 'index.html') {
    my $templatedir = bz_locations()->{'templatedir'};
    print <<EOT;

*** It appears that you still have an old index.html hanging around.
    Either the contents of this file should be moved into a template and 
    placed in the '$templatedir/en/custom' directory, or you should delete 
    the file.

EOT
  }

  # Delete old files that no longer need to exist

  # 2001-04-29 jake@bugzilla.org - Remove oldemailtech
  #   http://bugzilla.mozilla.org/show_bugs.cgi?id=71552
  if (-d 'shadow') {
    print "Removing shadow directory...\n";
    rmtree("shadow");
  }

  if (-e "$datadir/versioncache") {
    print "Removing versioncache...\n";
    unlink "$datadir/versioncache";
  }

  if (-e "$datadir/duplicates.rdf") {
    print "Removing duplicates.rdf...\n";
    unlink "$datadir/duplicates.rdf";
    unlink "$datadir/duplicates-old.rdf";
  }

  if (-e "$datadir/duplicates") {
    print "Removing duplicates directory...\n";
    rmtree("$datadir/duplicates");
  }

  _remove_empty_css_files();
  _convert_single_file_skins();
  _remove_dynamic_assets();
}

sub _remove_empty_css_files {
  my $skinsdir = bz_locations()->{'skinsdir'};
  foreach my $css_file (glob("$skinsdir/custom/*.css"),
    glob("$skinsdir/contrib/*/*.css"))
  {
    _remove_empty_css($css_file);
  }
}

# A simple helper for the update code that removes "empty" CSS files.
sub _remove_empty_css {
  my ($file)         = @_;
  my $basename       = basename($file);
  my $empty_contents = <<EOT;
/*
 * Custom rules for $basename.
 * The rules you put here override rules in that stylesheet.
 */
EOT
  if (length($empty_contents) == -s $file) {
    open(my $fh, '<', $file) or warn "$file: $!";
    my $file_contents;
    { local $/; $file_contents = <$fh>; }
    if ($file_contents eq $empty_contents) {
      print install_string('file_remove', {name => $file}), "\n";
      unlink $file or warn "$file: $!";
    }
  }
}

# We used to allow a single css file in the skins/contrib/ directory
# to be a whole skin.
sub _convert_single_file_skins {
  my $skinsdir = bz_locations()->{'skinsdir'};
  foreach my $skin_file (glob "$skinsdir/contrib/*.css") {
    my $dir_name = $skin_file;
    $dir_name =~ s/\.css$//;
    mkdir $dir_name or warn "$dir_name: $!";
    _rename_file($skin_file, "$dir_name/global.css");
  }
}

# delete all automatically generated css/js files to force recreation at the
# next request.
sub _remove_dynamic_assets {
  my @files = (
    glob(bz_locations()->{assetsdir} . '/*.css'),
    glob(bz_locations()->{assetsdir} . '/*.js'),
  );
  foreach my $file (@files) {
    unlink($file);
  }

  # remove old skins/assets directory
  my $old_path = bz_locations()->{skinsdir} . '/assets';
  if (-d $old_path) {
    foreach my $file (glob("$old_path/*.css")) {
      unlink($file);
    }
    rmdir($old_path);
  }
}

sub create_htaccess {
  _create_files(%{FILESYSTEM()->{htaccess}});

  # Repair old .htaccess files

  my $webdot_dir = bz_locations()->{'webdotdir'};

  # The public webdot IP address changed.
  my $webdot = new IO::File("$webdot_dir/.htaccess", 'r')
    || die "$webdot_dir/.htaccess: $!";
  my $webdot_data;
  { local $/; $webdot_data = <$webdot>; }
  $webdot->close;
  if ($webdot_data =~ /192\.20\.225\.10/) {
    print "Repairing $webdot_dir/.htaccess...\n";
    $webdot_data =~ s/192\.20\.225\.10/192.20.225.0\/24/g;
    $webdot = new IO::File("$webdot_dir/.htaccess", 'w') || die $!;
    print $webdot $webdot_data;
    $webdot->close;
  }
}

sub _rename_file {
  my ($from, $to) = @_;
  print install_string('file_rename', {from => $from, to => $to}), "\n";
  if (-e $to) {
    warn "$to already exists, not moving\n";
  }
  else {
    move($from, $to) or warn $!;
  }
}

# A helper for the above functions.
sub _create_files {
  my (%files) = @_;

  # It's not necessary to sort these, but it does make the
  # output of checksetup.pl look a bit nicer.
  foreach my $file (sort keys %files) {
    unless (-e $file) {
      print "Creating $file...\n";
      my $info = $files{$file};
      my $fh   = new IO::File($file, O_WRONLY | O_CREAT, $info->{perms}) || die $!;
      print $fh $info->{contents} if $info->{contents};
      $fh->close;
    }
  }
}

# If you ran a REALLY old version of Bugzilla, your chart files are in the
# wrong format. This code is a little messy, because it's very old, and
# when moving it into this module, I couldn't test it so I left it almost
# completely alone.
sub _update_old_charts {
  my ($datadir) = @_;
  print "Updating old chart storage format...\n";
  foreach my $in_file (glob("$datadir/mining/*")) {

    # Don't try and upgrade image or db files!
    next
      if (($in_file =~ /\.gif$/i)
      || ($in_file =~ /\.png$/i)
      || ($in_file =~ /\.db$/i)
      || ($in_file =~ /\.orig$/i));

    rename("$in_file", "$in_file.orig") or next;
    open(IN,  "<", "$in_file.orig") or next;
    open(OUT, '>', $in_file)        or next;

    # Fields in the header
    my @declared_fields;

    # Fields we changed to half way through by mistake
    # This list comes from an old version of collectstats.pl
    # This part is only for people who ran later versions of 2.11 (devel)
    my @intermediate_fields = qw(DATE UNCONFIRMED NEW ASSIGNED REOPENED
      RESOLVED VERIFIED CLOSED);

    # Fields we actually want (matches the current collectstats.pl)
    my @out_fields = qw(DATE NEW ASSIGNED REOPENED UNCONFIRMED RESOLVED
      VERIFIED CLOSED FIXED INVALID WONTFIX LATER REMIND
      DUPLICATE WORKSFORME MOVED);

    while (<IN>) {
      if (/^# fields?: (.*)\s$/) {
        @declared_fields = map uc, (split /\||\r/, $1);
        print OUT "# fields: ", join('|', @out_fields), "\n";
      }
      elsif (/^(\d+\|.*)/) {
        my @data = split(/\||\r/, $1);
        my %data;
        if (@data == @declared_fields) {

          # old format
          for my $i (0 .. $#declared_fields) {
            $data{$declared_fields[$i]} = $data[$i];
          }
        }
        elsif (@data == @intermediate_fields) {

          # Must have changed over at this point
          for my $i (0 .. $#intermediate_fields) {
            $data{$intermediate_fields[$i]} = $data[$i];
          }
        }
        elsif (@data == @out_fields) {

          # This line's fine - it has the right number of entries
          for my $i (0 .. $#out_fields) {
            $data{$out_fields[$i]} = $data[$i];
          }
        }
        else {
          print "Oh dear, input line $. of $in_file had "
            . scalar(@data)
            . " fields\nThis was unexpected.",
            " You may want to check your data files.\n";
        }

        print OUT join('|', map { defined($data{$_}) ? ($data{$_}) : "" } @out_fields),
          "\n";
      }
      else {
        print OUT;
      }
    }

    close(IN);
    close(OUT);
  }
}

# The old naming scheme has product names as mining file names; we rename them
# to product IDs.
sub _update_old_mining_filenames {
  my ($miningdir) = @_;
  my $dbh = Bugzilla->dbh;
  my @conversion_errors;

  # We use a dummy product instance with ID 0, representing all products
  my $product_all = {id => 0, name => '-All-'};

  print "Updating old charting data file names...";
  my @products = @{
    $dbh->selectall_arrayref(
      'SELECT id, name FROM products
                                                ORDER BY name', {Slice => {}}
    )
  };
  push(@products, $product_all);
  foreach my $product (@products) {
    if (-e File::Spec->catfile($miningdir, $product->{id})) {
      push(
        @conversion_errors,
        {
          product => $product,
          message => 'A file named "' . $product->{id} . '" already exists.'
        }
      );
    }
  }

  if (!@conversion_errors) {

    # Renaming mining files should work now without a hitch.
    foreach my $product (@products) {
      if (
        !rename(
          File::Spec->catfile($miningdir, $product->{name}),
          File::Spec->catfile($miningdir, $product->{id})
        )
        )
      {
        push(@conversion_errors, {product => $product, message => $!});
      }
    }
  }

  # Error reporting
  if (!@conversion_errors) {
    print " done.\n";
  }
  else {
    print " FAILED:\n";
    foreach my $error (@conversion_errors) {
      printf "Cannot rename charting data file for product %d (%s): %s\n",
        $error->{product}->{id}, $error->{product}->{name}, $error->{message};
    }
    print "You need to empty the \"$miningdir\" directory, then run\n",
      "   collectstats.pl --regenerate\n", "in order to clean this up.\n";
  }
}

sub fix_dir_permissions {
  my ($dir) = @_;
  return if ON_WINDOWS;

  # Note that _get_owner_and_group is always silent here.
  my ($owner_id, $group_id) = _get_owner_and_group();

  my $perms;
  my $fs = FILESYSTEM();
  if ($perms = $fs->{recurse_dirs}->{$dir}) {
    _fix_perms_recursively($dir, $owner_id, $group_id, $perms);
  }
  elsif ($perms = $fs->{all_dirs}->{$dir}) {
    _fix_perms($dir, $owner_id, $group_id, $perms);
  }
  else {
    # Do nothing. We know nothing about this directory.
    warn "Unknown directory $dir";
  }
}

sub fix_file_permissions {
  my ($file) = @_;
  return if ON_WINDOWS;
  my $perms = FILESYSTEM()->{all_files}->{$file}->{perms};

  # Note that _get_owner_and_group is always silent here.
  my ($owner_id, $group_id) = _get_owner_and_group();
  _fix_perms($file, $owner_id, $group_id, $perms);
}

sub fix_all_file_permissions {
  my ($output) = @_;

  # _get_owner_and_group also checks that the webservergroup is valid.
  my ($owner_id, $group_id) = _get_owner_and_group($output);

  return if ON_WINDOWS;

  my $fs           = FILESYSTEM();
  my %files        = %{$fs->{all_files}};
  my %dirs         = %{$fs->{all_dirs}};
  my %recurse_dirs = %{$fs->{recurse_dirs}};

  print get_text('install_file_perms_fix') . "\n" if $output;

  foreach my $dir (sort keys %dirs) {
    next unless -d $dir;
    _fix_perms($dir, $owner_id, $group_id, $dirs{$dir});
  }

  foreach my $pattern (sort keys %recurse_dirs) {
    my $perms = $recurse_dirs{$pattern};

    # %recurse_dirs supports globs
    foreach my $dir (glob $pattern) {
      next unless -d $dir;
      _fix_perms_recursively($dir, $owner_id, $group_id, $perms);
    }
  }

  foreach my $file (sort keys %files) {

    # %files supports globs
    foreach my $filename (glob $file) {

      # Don't touch directories.
      next if -d $filename || !-e $filename;
      _fix_perms($filename, $owner_id, $group_id, $files{$file}->{perms});
    }
  }

  _fix_cvs_dirs($owner_id, '.');
}

sub _get_owner_and_group {
  my ($output) = @_;
  my $group_id = _check_web_server_group($output);
  return () if ON_WINDOWS;

  my $owner_id = POSIX::getuid();
  $group_id = POSIX::getgid() unless defined $group_id;
  return ($owner_id, $group_id);
}

# A helper for fix_all_file_permissions
sub _fix_cvs_dirs {
  my ($owner_id, $dir) = @_;
  my $owner_gid = POSIX::getgid();
  find(
    {
      no_chdir => 1,
      wanted   => sub {
        my $name = $File::Find::name;
        if ( $File::Find::dir =~ /\/CVS/
          || $_ eq '.cvsignore'
          || (-d $name && $_ =~ /CVS$/))
        {
          my $perms = 0600;
          if (-d $name) {
            $perms = 0700;
          }
          _fix_perms($name, $owner_id, $owner_gid, $perms);
        }
      }
    },
    $dir
  );
}

sub _fix_perms {
  my ($name, $owner, $group, $perms) = @_;

  #printf ("Changing $name to %o\n", $perms);

  # The webserver should never try to chown files.
  if (Bugzilla->usage_mode == USAGE_MODE_CMDLINE) {
    chown $owner, $group, $name
      or warn install_string('chown_failed', {path => $name, error => $!}) . "\n";
  }
  chmod $perms, $name
    or warn install_string('chmod_failed', {path => $name, error => $!}) . "\n";
}

sub _fix_perms_recursively {
  my ($dir, $owner_id, $group_id, $perms) = @_;

  # Set permissions on the directory itself.
  _fix_perms($dir, $owner_id, $group_id, $perms->{dirs});

  # Now recurse through the directory and set the correct permissions
  # on subdirectories and files.
  find(
    {
      no_chdir => 1,
      wanted   => sub {
        my $name = $File::Find::name;
        if (-d $name) {
          _fix_perms($name, $owner_id, $group_id, $perms->{dirs});
        }
        else {
          _fix_perms($name, $owner_id, $group_id, $perms->{files});
        }
      }
    },
    $dir
  );
}

sub _check_web_server_group {
  my ($output) = @_;

  my $group    = Bugzilla->localconfig->{'webservergroup'};
  my $filename = bz_locations()->{'localconfig'};
  my $group_id;

  # If we are on Windows, webservergroup does nothing
  if (ON_WINDOWS && $group && $output) {
    print "\n\n" . get_text('install_webservergroup_windows') . "\n\n";
  }

  # If we're not on Windows, make sure that webservergroup isn't
  # empty.
  elsif (!ON_WINDOWS && !$group && $output) {
    print "\n\n" . get_text('install_webservergroup_empty') . "\n\n";
  }

  # If we're not on Windows, make sure we are actually a member of
  # the webservergroup.
  elsif (!ON_WINDOWS && $group) {
    $group_id = getgrnam($group);
    ThrowCodeError('invalid_webservergroup', {group => $group})
      unless defined $group_id;

    # If on unix, see if we need to print a warning about a webservergroup
    # that we can't chgrp to
    if ($output && $< != 0 && !grep($_ eq $group_id, split(" ", $)))) {
      print "\n\n" . get_text('install_webservergroup_not_in') . "\n\n";
    }
  }

  return $group_id;
}

1;

__END__

=head1 NAME

Bugzilla::Install::Filesystem - Fix up the filesystem during
  installation.

=head1 DESCRIPTION

This module is used primarily by L<checksetup.pl> to modify the 
filesystem during installation, including creating the data/ directory.

=head1 SUBROUTINES

=over

=item C<update_filesystem({ index_html => 0 })>

Description: Creates all the directories and files that Bugzilla
             needs to function but doesn't ship with. Also does
             any updates to these files as necessary during an
             upgrade.

Params:      C<index_html> - Whether or not we should create
               the F<index.html> file.

Returns:     nothing

=item C<create_htaccess()>

Description: Creates all of the .htaccess files for Apache,
             in the various Bugzilla directories. Also updates
             the .htaccess files if they need updating.

Params:      none

Returns:     nothing

=item C<fix_all_file_permissions($output)>

Description: Sets all the file permissions on all of Bugzilla's files
             to what they should be. Note that permissions are different
             depending on whether or not C<$webservergroup> is set
             in F<localconfig>.

Params:      C<$output> - C<true> if you want this function to print
                 out information about what it's doing.

Returns:     nothing

=item C<fix_dir_permissions>

Given the name of a directory, its permissions will be fixed according to
how they are supposed to be set in Bugzilla's current configuration.
If it fails to set the permissions, a warning will be printed to STDERR.

=item C<fix_file_permissions>

Given the name of a file, its permissions will be fixed according to
how they are supposed to be set in Bugzilla's current configuration.
If it fails to set the permissions, a warning will be printed to STDERR.

=back

=head1 B<Methods in need of POD>

=over

=item CGI_WRITE

=item DIR_WS_SERVE

=item DIR_ALSO_WS_SERVE

=item WS_SERVE

=item FILESYSTEM

=item WS_EXECUTE

=item CGI_READ

=item DIR_CGI_READ

=item DIR_CGI_WRITE

=item DIR_CGI_OVERWRITE

=back